U19CS918 CLOUD COMPUTING 3003

UNIT I OVERVIEW OF CLOUD COMPUTING

Brief history and evolution - History of Cloud Computing, Evolution of Cloud

Computing, Traditional vs. Cloud Computing - Why Cloud Computing, Cloud service
models (IaaS, PaaS & SaaS). Cloud deployment models (Public, Private, Hybrid and
Community Cloud), Benefits and Challenges of Cloud Computing - Introduction to
AWS Public Cloud Vendor.

1.1 Cloud Computing

Cloud Computing tutorial provides basic and advanced concepts of Cloud

Computing. Our Cloud Computing tutorial is designed for beginners and
professionals.

Cloud computing is a virtualization-based technology that allows us to

create, configure, and customize applications via an internet connection. The
cloud technology includes a development platform, hard disk, software
application, and database.

What is Cloud Computing

The term cloud refers to a network or the internet. It is a technology that
uses remote servers on the internet to store, manage, and access data
online rather than local drives. The data can be anything such as files,
images, documents, audio, video, and more.

There are the following operations that we can do using cloud computing:

o Developing new applications and services

o Storage, back up, and recovery of data
 o Hosting blogs and websites
o Delivery of software on demand
o Analysis of data
o Streaming videos and audios

1.2 Why Cloud Computing?

Small as well as large IT companies, follow the traditional methods to provide
the IT infrastructure. That means for any IT company, we need a Server
Room that is the basic need of IT companies.

In that server room, there should be a database server, mail server,

networking, firewalls, routers, modem, switches, QPS (Query Per Second
means how much queries or load will be handled by the server), configurable
system, high net speed, and the maintenance engineers.

To establish such IT infrastructure, we need to spend lots of money. To

overcome all these problems and to reduce the IT infrastructure cost, Cloud
Computing comes into existence.
1.3 Characteristics of Cloud Computing
The characteristics of cloud computing are given below:

1) Agility

The cloud works in a distributed computing environment. It shares

resources among users and works very fast.

2) High availability and reliability

The availability of servers is high and more reliable because the chances of
infrastructure failure are minimum.

3) High Scalability

Cloud offers "on-demand" provisioning of resources on a large scale,

without having engineers for peak loads.

4) Multi-Sharing

With the help of cloud computing, multiple users and applications can
work more efficiently with cost reductions by sharing common
infrastructure.

5) Device and Location Independence

Cloud computing enables the users to access systems using a web browser
regardless of their location or what device they use e.g. PC, mobile phone,
etc. As infrastructure is off-site (typically provided by a third-party) and
accessed via the Internet, users can connect from anywhere.

6) Maintenance

Maintenance of cloud computing applications is easier, since they do not

need to be installed on each user's computer and can be accessed
from different places. So, it reduces the cost also.

7) Low Cost

By using cloud computing, the cost will be reduced because to take the
services of cloud computing, IT company need not to set its own
infrastructure and pay-as-per usage of resources.

8) Services in the pay-per-use mode

Application Programming Interfaces (APIs) are provided to the users so
that they can access services on the cloud by using these APIs and pay
the charges as per the usage of services.

1.4 Advantages and Disadvantages of Cloud

Computing
Advantages of Cloud Computing
As we all know that Cloud computing is trending technology. Almost every
company switched their services on the cloud to rise the company growth.

Here, we are going to discuss some important advantages of Cloud

Computing-

1) Back-up and restore data

Once the data is stored in the cloud, it is easier to get back-up and restore
that data using the cloud.
2) Improved collaboration

Cloud applications improve collaboration by allowing groups of people to

quickly and easily share information in the cloud via shared storage.

3) Excellent accessibility

Cloud allows us to quickly and easily access store information anywhere,

anytime in the whole world, using an internet connection. An internet cloud
infrastructure increases organization productivity and efficiency by ensuring
that our data is always accessible.

4) Low maintenance cost

Cloud computing reduces both hardware and software maintenance costs for
organizations.

5) Mobility

Cloud computing allows us to easily access all cloud data via mobile.

6) IServices in the pay-per-use model

Cloud computing offers Application Programming Interfaces (APIs) to the

users for access services on the cloud and pays the charges as per the usage
of service.

7) Unlimited storage capacity

Cloud offers us a huge amount of storing capacity for storing our important
data such as documents, images, audio, video, etc. in one place.

8) Data security

Data security is one of the biggest advantages of cloud computing. Cloud

offers many advanced features related to security and ensures that data is
securely stored and handled.

Disadvantages of Cloud Computing

A list of the disadvantage of cloud computing is given below -
1) Internet Connectivity

As you know, in cloud computing, every data (image, audio, video, etc.) is
stored on the cloud, and we access these data through the cloud by using
the internet connection. If you do not have good internet connectivity, you
cannot access these data. However, we have no any other way to access
data from the cloud.

2) Vendor lock-in

Vendor lock-in is the biggest disadvantage of cloud computing. Organizations

may face problems when transferring their services from one vendor to
another. As different vendors provide different platforms, that can cause
difficulty moving from one cloud to another.

3) Limited Control

As we know, cloud infrastructure is completely owned, managed, and

monitored by the service provider, so the cloud users have less control over
the function and execution of services within a cloud infrastructure.

4) Security

Although cloud service providers implement the best security standards to

store important information. But, before adopting cloud technology, you
should be aware that you will be sending all your organization's sensitive
information to a third party, i.e., a cloud computing service provider. While
sending the data on the cloud, there may be a chance that your
organization's information is hacked by Hackers.

1.5 History of Cloud Computing

Before emerging the cloud computing, there was Client/Server computing
which is basically a centralized storage in which all the software applications,
all the data and all the controls are resided on the server side.

If a single user wants to access specific data or run a program, he/she need
to connect to the server and then gain appropriate access, and then he/she
can do his/her business.

Then after, distributed computing came into picture, where all the computers
are networked together and share their resources when needed.

On the basis of above computing, there was emerged of cloud computing

concepts that later implemented.
At around in 1961, John MacCharty suggested in a speech at MIT that
computing can be sold like a utility, just like a water or electricity. It was a
brilliant idea, but like all brilliant ideas, it was ahead if its time, as for the
next few decades, despite interest in the model, the technology simply was
not ready for it.

But of course time has passed and the technology caught that idea and after
few years we mentioned that:

In 1999, Salesforce.com started delivering of applications to users using a

simple website. The applications were delivered to enterprises over the
Internet, and this way the dream of computing sold as utility were true.

In 2002, Amazon started Amazon Web Services, providing services like

storage, computation and even human intelligence. However, only starting
with the launch of the Elastic Compute Cloud in 2006 a truly commercial
service open to everybody existed.

In 2009, Google Apps also started to provide cloud computing enterprise

applications.

Of course, all the big players are present in the cloud computing evolution,
some were earlier, some were later. In 2009, Microsoft launched Windows
Azure, and companies like Oracle and HP have all joined the game. This
proves that today, cloud computing has become mainstream.

1.5.1 Evolution of Cloud Computing

Difficulty Level: Easy

 Last Updated: 14 May, 2020

 Cloud computing is all about renting computing services. This idea first
came in the 1950s. In making cloud computing what it is today, five
technologies played a vital role. These are distributed systems and its
peripherals, virtualization, web 2.0, service orientation, and utility
computing.

Distributed Systems:

 It is a composition of multiple independent systems but all of them are

depicted as a single entity to the users. The purpose of distributed systems
is to share resources and also use them effectively and efficiently.
Distributed systems possess characteristics such as scalability, concurrency,
continuous availability, heterogeneity, and independence in failures. But the
main problem with this system was that all the systems were required to be
present at the same geographical location. Thus to solve this problem,
distributed computing led to three more types of computing and they were-
Mainframe computing, cluster computing, and grid computing.

Mainframe computing:

 Mainframes which first came into existence in 1951 are highly powerful and
reliable computing machines. These are responsible for handling large data
such as massive input-output operations. Even today these are used for bulk
processing tasks such as online transactions etc. These systems have almost
no downtime with high fault tolerance. After distributed computing, these
increased the processing capabilities of the system. But these were very
expensive. To reduce this cost, cluster computing came as an alternative to
mainframe technology. Cluster computing: In 1980s, cluster computing came
as an alternative to mainframe computing. Each machine in the cluster was
connected to each other by a network with high bandwidth. These were way
cheaper than those mainframe systems. These were equally capable of high
computations. Also, new nodes could easily be added to the cluster if it was
required. Thus, the problem of the cost was solved to some extent but the
problem related to geographical restrictions still pertained. To solve this, the
concept of grid computing was introduced.

Grid computing:

 In 1990s, the concept of grid computing was introduced. It means that

different systems were placed at entirely different geographical locations
and these all were connected via the internet. These systems belonged to
different organizations and thus the grid consisted of heterogeneous nodes.
Although it solved some problems but new problems emerged as the
distance between the nodes increased. The main problem which was
encountered was the low availability of high bandwidth connectivity and with
it other network associated issues. Thus. cloud computing is often referred to
as “Successor of grid computing”.

Virtualization:

 It was introduced nearly 40 years back. It refers to the process of creating a

virtual layer over the hardware which allows the user to run multiple
instances simultaneously on the hardware. It is a key technology used in
cloud computing. It is the base on which major cloud computing services
such as Amazon EC2, VMware vCloud, etc work on. Hardware virtualization is
still one of the most common types of virtualization.

Web 2.0:
 It is the interface through which the cloud computing services interact with
the clients. It is because of Web 2.0 that we have interactive and dynamic
web pages. It also increases flexibility among web pages. Popular examples
of web 2.0 include Google Maps, Facebook, Twitter, etc. Needless to say,
social media is possible because of this technology only. In gained major
popularity in 2004.

Service orientation:

 It acts as a reference model for cloud computing. It supports low-cost,

flexible, and evolvable applications. Two important concepts were introduced
in this computing model. These were Quality of Service (QoS) which also
includes the SLA (Service Level Agreement) and Software as a Service
(SaaS).

Utility computing:

 It is a computing model that defines service provisioning techniques for

services such as compute services along with other major services such as
storage, infrastructure, etc which are provisioned on a pay-per-use basis.

1.6 Cloud Computing Architecture

As we know, cloud computing technology is used by both small and large
organizations to store the information in cloud and access it from
anywhere at anytime using the internet connection.

Cloud computing architecture is a combination of service-oriented

architecture and event-driven architecture.

Cloud computing architecture is divided into the following two parts -

o Front End
o Back End

The below diagram shows the architecture of cloud computing -

Front End
The front end is used by the client. It contains client-side interfaces and
applications that are required to access the cloud computing platforms. The
front end includes web servers (including Chrome, Firefox, internet explorer,
etc.), thin & fat clients, tablets, and mobile devices.

Back End
The back end is used by the service provider. It manages all the resources
that are required to provide cloud computing services. It includes a huge
amount of data storage, security mechanism, virtual machines, deploying
models, servers, traffic control mechanisms, etc.

Note: Both front end and back end are connected to others through a network, generally
using the internet connection.

Components of Cloud Computing Architecture

There are the following components of cloud computing architecture -

1. Client Infrastructure
Client Infrastructure is a Front end component. It provides GUI (Graphical
User Interface) to interact with the cloud.

2. Application

The application may be any software or platform that a client wants to

access.

3. Service

A Cloud Services manages that which type of service you access according
to the client’s requirement.

Cloud computing offers the following three type of services:

i. Software as a Service (SaaS) – It is also known as cloud application

services. Mostly, SaaS applications run directly through the web browser
means we do not require to download and install these applications. Some
important example of SaaS is given below –

Example: Google Apps, Salesforce Dropbox, Slack, Hubspot, Cisco WebEx.

ii. Platform as a Service (PaaS) – It is also known as cloud

platform services. It is quite similar to SaaS, but the difference is that PaaS
provides a platform for software creation, but using SaaS, we can access
software over the internet without the need of any platform.

Example: Windows Azure, Force.com, Magento Commerce Cloud, OpenShift.

iii. Infrastructure as a Service (IaaS) – It is also known as cloud

infrastructure services. It is responsible for managing applications data,
middleware, and runtime environments.

Example: Amazon Web Services (AWS) EC2, Google Compute Engine (GCE),
Cisco Metapod.

4. Runtime Cloud

Runtime Cloud provides the execution and runtime environment to the

virtual machines.

5. Storage

Storage is one of the most important components of cloud computing. It

provides a huge amount of storage capacity in the cloud to store and
manage data.
6. Infrastructure

It provides services on the host level, application level, and network

level. Cloud infrastructure includes hardware and software components such
as servers, storage, network devices, virtualization software, and other
storage resources that are needed to support the cloud computing model.

7. Management

Management is used to manage components such as application, service,

runtime cloud, storage, infrastructure, and other security issues in the
backend and establish coordination between them.

8. Security

Security is an in-built back end component of cloud computing. It implements

a security mechanism in the back end.

9. Internet

The Internet is medium through which front end and back end can interact
and communicate with each other.

Difference between Cloud Computing and Grid

Computing
Cloud Computing
Cloud computing uses a client-server architecture to deliver computing
resources such as servers, storage, databases, and software over the cloud
(Internet) with pay-as-you-go pricing.

Cloud computing becomes a very popular option for organizations by

providing various advantages, including cost-saving, increased productivity,
efficiency, performance, data back-ups, disaster recovery, and security.
Grid Computing
Grid computing is also called as "distributed computing." It links multiple
computing resources (PC's, workstations, servers, and storage elements)
together and provides a mechanism to access them.

The main advantages of grid computing are that it increases user

productivity by providing transparent access to resources, and work can be
completed more quickly.
Let's understand the difference between cloud computing and grid
computing.

Cloud Computing Grid Computing

Cloud Computing follows client- Grid computing follows a distributed

server computing architecture. computing architecture.

Scalability is high. Scalability is normal.

Cloud Computing is more flexible Grid Computing is less flexible than cloud
than grid computing. computing.

Cloud operates as a centralized Grid operates as a decentralized

management system. management system.
 In cloud computing, cloud servers are In Grid computing, grids are owned and
owned by infrastructure providers. managed by the organization.

Cloud computing uses services like Grid computing uses systems like
Iaas, PaaS, and SaaS. distributed computing, distributed
information, and distributed pervasive.

Cloud Computing is Service-oriented. Grid Computing is Application-oriented.

It is accessible through standard web It is accessible through grid middleware.

protocols.

1.7 How does cloud computing work

Assume that you are an executive at a very big corporation. Your particular
responsibilities include to make sure that all of your employees have the
right hardware and software they need to do their jobs. To buy computers for
everyone is not enough. You also have to purchase software as well as
software licenses and then provide these softwares to your employees as
they require. Whenever you hire a new employee, you need to buy more
software or make sure your current software license allows another user. It is
so stressful that you have to spend lots of money.

But, there may be an alternative for executives like you. So, instead of
installing a suite of software for each computer, you just need to load one
application. That application will allow the employees to log-in into a Web-
based service which hosts all the programs for the user that is required for
his/her job. Remote servers owned by another company and that will run
everything from e-mail to word processing to complex data analysis
programs. It is called cloud computing, and it could change the entire
computer industry.
In a cloud computing system, there is a significant workload shift. Local
computers have no longer to do all the heavy lifting when it comes to run
applications. But cloud computing can handle that much heavy load easily
and automatically. Hardware and software demands on the user's side
decrease. The only thing the user's computer requires to be able to run is the
cloud computing interface software of the system, which can be as simple as
a Web browser and the cloud's network takes care of the rest.

1.8 Cloud Computing Applications

Cloud service providers provide various applications in the field of art,
business, data storage and backup services, education, entertainment,
management, social networking, etc.

The most widely used cloud computing applications are given below -
1. Art Applications
Cloud computing offers various art applications for quickly and easily
design attractive cards, booklets, and images. Some most commonly
used cloud art applications are given below:

i Moo

Moo is one of the best cloud art applications. It is used for designing and
printing business cards, postcards, and mini cards.

ii. Vistaprint

Vistaprint allows us to easily design various printed marketing products such

as business cards, Postcards, Booklets, and wedding invitations cards.

iii. Adobe Creative Cloud

Adobe creative cloud is made for designers, artists, filmmakers, and other
creative professionals. It is a suite of apps which includes PhotoShop image
editing programming, Illustrator, InDesign, TypeKit, Dreamweaver, XD, and
Audition.
2. Business Applications
Business applications are based on cloud service providers. Today, every
organization requires the cloud business application to grow their business. It
also ensures that business applications are 24*7 available to users.

There are the following business applications of cloud computing -

i. MailChimp

MailChimp is an email publishing platform which provides various options

to design, send, and save templates for emails.

iii. Salesforce

Salesforce platform provides tools for sales, service, marketing, e-commerce,

and more. It also provides a cloud development platform.

iv. Chatter

Chatter helps us to share important information about the organization in

real time.

v. Bitrix24

Bitrix24 is a collaboration platform which provides communication,

management, and social collaboration tools.

vi. Paypal

Paypal offers the simplest and easiest online payment mode using a secure
internet account. Paypal accepts the payment through debit cards, credit
cards, and also from Paypal account holders.

vii. Slack

Slack stands for Searchable Log of all Conversation and Knowledge. It

provides a user-friendly interface that helps us to create public and private
channels for communication.

viii. Quickbooks

Quickbooks works on the terminology "Run Enterprise anytime,

anywhere, on any device." It provides online accounting solutions for the
business. It allows more than 20 users to work simultaneously on the same
system.

3. Data Storage and Backup Applications

Cloud computing allows us to store information (data, files, images, audios,
and videos) on the cloud and access this information using an internet
connection. As the cloud provider is responsible for providing security, so
they offer various backup recovery application for retrieving the lost data.

A list of data storage and backup applications in the cloud are given below -

i. Box.com

Box provides an online environment for secure content management,

workflow, and collaboration. It allows us to store different files such as
Excel, Word, PDF, and images on the cloud. The main advantage of using box
is that it provides drag & drop service for files and easily integrates with
Office 365, G Suite, Salesforce, and more than 1400 tools.

ii. Mozy

Mozy provides powerful online backup solutions for our personal and
business data. It schedules automatically back up for each day at a specific
time.

iii. Joukuu

Joukuu provides the simplest way to share and track cloud-based backup
files. Many users use joukuu to search files, folders, and collaborate on
documents.

iv. Google G Suite

Google G Suite is one of the best cloud storage and backup application. It
includes Google Calendar, Docs, Forms, Google+, Hangouts, as well as cloud
storage and tools for managing cloud apps. The most popular app in the
Google G Suite is Gmail. Gmail offers free email services to users.

4. Education Applications
Cloud computing in the education sector becomes very popular. It offers
various online distance learning platforms and student information
portals to the students. The advantage of using cloud in the field of
education is that it offers strong virtual classroom environments, Ease of
accessibility, secure data storage, scalability, greater reach for the students,
and minimal hardware requirements for the applications.

There are the following education applications offered by the cloud -

i. Google Apps for Education

Google Apps for Education is the most widely used platform for free web-
based email, calendar, documents, and collaborative study.

ii. Chromebooks for Education

Chromebook for Education is one of the most important Google's projects. It

is designed for the purpose that it enhances education innovation.

iii. Tablets with Google Play for Education

It allows educators to quickly implement the latest technology solutions into

the classroom and make it available to their students.

iv. AWS in Education

AWS cloud provides an education-friendly environment to universities,

community colleges, and schools.

5. Entertainment Applications
Entertainment industries use a multi-cloud strategy to interact with the
target audience. Cloud computing offers various entertainment applications
such as online games and video conferencing.

i. Online games

Today, cloud gaming becomes one of the most important entertainment

media. It offers various online games that run remotely from the cloud. The
best cloud gaming services are Shaow, GeForce Now, Vortex, Project xCloud,
and PlayStation Now.

ii. Video Conferencing Apps

Video conferencing apps provides a simple and instant connected

experience. It allows us to communicate with our business partners, friends,
and relatives using a cloud-based video conferencing. The benefits of using
video conferencing are that it reduces cost, increases efficiency, and
removes interoperability.
6. Management Applications
Cloud computing offers various cloud management tools which help admins
to manage all types of cloud activities, such as resource deployment, data
integration, and disaster recovery. These management tools also provide
administrative control over the platforms, applications, and infrastructure.

Some important management applications are -

i. Toggl
Toggl helps users to track allocated time period for a particular project.

ii. Evernote
Evernote allows you to sync and save your recorded notes, typed notes, and
other notes in one convenient place. It is available for both free as well as a
paid version.

It uses platforms like Windows, macOS, Android, iOS, Browser, and Unix.

iii. Outright
Outright is used by management users for the purpose of accounts. It helps
to track income, expenses, profits, and losses in real-time environment.

iv. GoToMeeting
GoToMeeting provides Video Conferencing and online meeting apps,
which allows you to start a meeting with your business partners from
anytime, anywhere using mobile phones or tablets. Using GoToMeeting app,
you can perform the tasks related to the management such as join meetings
in seconds, view presentations on the shared screen, get alerts for upcoming
meetings, etc.

7. Social Applications
Social cloud applications allow a large number of users to connect with each
other using social networking applications such as Facebook, Twitter,
Linkedln, etc.

There are the following cloud based social applications -

i. Facebook
Facebook is a social networking website which allows active users to
share files, photos, videos, status, more to their friends, relatives, and
business partners using the cloud storage system. On Facebook, we will
always get notifications when our friends like and comment on the posts.

ii. Twitter

Twitter is a social networking site. It is a microblogging system. It allows

users to follow high profile celebrities, friends, relatives, and receive news. It
sends and receives short posts called tweets.

iii. Yammer

Yammer is the best team collaboration tool that allows a team of

employees to chat, share images, documents, and videos.

iv. LinkedIn

LinkedIn is a social network for students, freshers, and professionals.

1.9 What are the Security Risks of Cloud

Computing
Cloud computing provides various advantages, such as improved
collaboration, excellent accessibility, Mobility, Storage capacity, etc. But
there are also security risks in cloud computing.

Some most common Security Risks of Cloud Computing are given below-

Data Loss
Data loss is the most common cloud security risks of cloud computing. It is
also known as data leakage. Data loss is the process in which data is being
deleted, corrupted, and unreadable by a user, software, or application. In a
cloud computing environment, data loss occurs when our sensitive data is
somebody else's hands, one or more data elements can not be utilized by
the data owner, hard disk is not working properly, and software is not
updated.

Hacked Interfaces and Insecure APIs

As we all know, cloud computing is completely depends on Internet, so it is
compulsory to protect interfaces and APIs that are used by external users.
APIs are the easiest way to communicate with most of the cloud services. In
cloud computing, few services are available in the public domain. These
services can be accessed by third parties, so there may be a chance that
these services easily harmed and hacked by hackers.

Data Breach
Data Breach is the process in which the confidential data is viewed, accessed, or stolen by the
third party without any authorization, so organization's data is hacked by the hackers.

Vendor lock-in
Vendor lock-in is the of the biggest security risks in cloud computing. Organizations may face
problems when transferring their services from one vendor to another. As different vendors
provide different platforms, that can cause difficulty moving one cloud to another.

Increased complexity strains IT staff

Migrating, integrating, and operating the cloud services is complex for the IT staff. IT staff must
require the extra capability and skills to manage, integrate, and maintain the data to the cloud.

Spectre & Meltdown

Spectre & Meltdown allows programs to view and steal data which is currently processed on
computer. It can run on personal computers, mobile devices, and in the cloud. It can store the
password, your personal information such as images, emails, and business documents in the
memory of other running programs.

Denial of Service (DoS) attacks

Denial of service (DoS) attacks occur when the system receives too much traffic to buffer the
server. Mostly, DoS attackers target web servers of large organizations such as banking sectors,
media companies, and government organizations. To recover the lost data, DoS attackers charge
a great deal of time and money to handle the data.

Account hijacking
Account hijacking is a serious security risk in cloud computing. It is the
process in which individual user's or organization's cloud account (bank
account, e-mail account, and social media account) is stolen by hackers. The
hackers use the stolen account to perform unauthorized activities.
1.10 Types of Cloud
Cloud computing is a revolutionary technology transforming how we store,
access, and process data. It simply refers to delivering computing resources,
such as servers, storage, databases, software, and applications, over the
Internet. Cloud computing uses a network of remote computer systems
housed on the net to save and process data rather than relying on physical
infrastructure.

Cloud service companies use advanced security techniques, which include

encryption, firewalls, and access restrictions, to secure your data from
unauthorized access. Moreover, because your information is saved in the
cloud, it is secure even if your nearby devices are damaged, misplaced, or
stolen. Redundancy and cloud backups guarantee that your data may be
restored promptly and effectively in case of any unexpected situations.

Types of Cloud
There are the following 5 types of cloud that you can deploy according to the
organization's needs-

o Public Cloud
o Private Cloud
o Hybrid Cloud
o Community Cloud
o Multi Cloud
Public Cloud
Public cloud is open to all to store and access information via the Internet
using the pay-per-usage method.

In public cloud, computing resources are managed and operated by the

Cloud Service Provider (CSP). The CSP looks after the supporting
infrastructure and ensures that the resources are accessible to and scalable
for the users.

Due to its open architecture, anyone with an internet connection may use
the public cloud, regardless of location or company size. Users can use the
CSP's numerous services, store their data, and run apps. By using a pay-per-
usage strategy, customers can be assured that they will only be charged for
the resources they actually use, which is a smart financial choice.

Example: Amazon elastic compute cloud (EC2), IBM SmartCloud Enterprise,

Microsoft, Google App Engine, Windows Azure Services Platform.

Characteristics of Public Cloud

The public cloud has the following key characteristics:
 o Accessibility: Public cloud services are available to anyone with an internet
connection. Users can access their data and programs at any time and from
anywhere.
o Shared Infrastructure: Several users share the infrastructure in public
cloud settings. Cost reductions and effective resource use are made possible
by this.
o Scalability: By using the public cloud, users can easily adjust the resources
they need based on their requirements, allowing for quick scaling up or down.
o Pay-per-Usage: When using the public cloud, payment is based on usage,
so users only pay for the resources they actually use. This helps optimize
costs and eliminates the need for upfront investments.
o Managed by Service Providers: Cloud service providers manage and
maintain public cloud infrastructure. They handle hardware maintenance,
software updates, and security tasks, relieving users of these responsibilities.
o Reliability and Redundancy: Public cloud providers ensure high reliability
by implementing redundant systems and multiple data centers. By doing this,
the probability of losing data and experiencing service disruptions is reduced.
o Security Measures: Public cloud providers implement robust security
measures to protect user data. These include encryption, access controls,
and regular security audits.

Advantages of Public Cloud

There are the following advantages of Public Cloud -

o Public cloud is owned at a lower cost than the private and hybrid cloud.
o Public cloud is maintained by the cloud service provider, so do not need to
worry about the maintenance.
o Public cloud is easier to integrate. Hence it offers a better flexibility approach
to consumers.
o Public cloud is location independent because its services are delivered
through the internet.
 o Public cloud is highly scalable as per the requirement of computing
resources.
o It is accessible by the general public, so there is no limit to the number of
users.
o Rapid deployment of services and applications.
o Reduced time and effort in hardware procurement and setup.
o The cloud provider offers a range of services and resources that you can avail
of.
o Built-in redundancy and resilience for enhanced reliability.

Disadvantages of Public Cloud

o Public Cloud is less secure because resources are shared publicly.
o Performance depends upon the high-speed internet network link to the cloud
provider.
o The data is not under the control of the client.
o Dependency on the cloud service provider for availability and service level
agreements.
o Compliance challenges in meeting industry-specific regulations and
standards.
o Risk of vendor lock-in and limited portability of applications and data.
o Concerns about data privacy and confidentiality.
o Potential for unexpected costs with usage-based pricing models.
o Lack of customization options and flexibility compared to private or hybrid
cloud environments.
o Reliance to the cloud provider's support and responsiveness for issue
resolution.

Private Cloud
Private cloud is also known as an internal cloud or corporate cloud. It is
used by organizations to build and manage their own data centers internally
or by the third party. It can be deployed using Opensource tools such as
Openstack and Eucalyptus.
Examples: VMware vSphere, OpenStack, Microsoft Azure Stack, Oracle
Cloud at Customer, and IBM Cloud Private.

Based on the location and management, National Institute of Standards and

Technology (NIST) divide private cloud into the following two parts-

o On-premise private cloud: An on-premise private cloud is situated within

the physical infrastructure of the organization. It involves setting up and
running a specific data center that offers cloud services just for internal
usage by the company. The infrastructure is still completely under the hands
of the organization, which gives them the freedom to modify and set it up in
any way they see fit. Organizations can successfully manage security and
compliance issues with this degree of control. However, on-premise private
cloud setup and management necessitate significant hardware, software, and
IT knowledge expenditures.
o Outsourced private cloud: An outsourced private cloud involves partnering
with a third-party service provider to host and manage the cloud
infrastructure on behalf of the organization. The provider may operate the
private cloud in their data center or a colocation facility. In this arrangement,
 the organization benefits from the expertise and resources of the service
provider, alleviating the burden of infrastructure management. The
outsourced private cloud model offers scalability, as the provider can adjust
resources based on the organization's needs. Due to its flexibility, it is a
desirable choice for businesses that desire the advantages of a private cloud
deployment without the initial capital outlay and ongoing maintenance
expenses involved with an on-premise implementation.

Compared to public cloud options, both on-premise and external private

clouds give businesses more control over their data, apps, and security.
Private clouds are particularly suitable for organizations with strict
compliance requirements, sensitive data, or specialized workloads that
demand high levels of customization and security.

Characteristics of Private Cloud

The private cloud has the following key characteristics:

o Exclusive Use: Private cloud is dedicated to a single organization, ensuring

the resources and services are tailored to its needs. It is like having a
personal cloud environment exclusively for that organization.
o Control and Security: Private cloud offers organizations higher control and
security than public cloud options. Organizations have more control over data
governance, access controls, and security measures.
o Customization and Flexibility: Private cloud allows organizations to
customize the infrastructure according to their specific requirements. They
can configure resources, networks, and storage to optimize performance and
efficiency.
o Scalability and Resource Allocation: The private cloud can scale and
allocate resources. According to demand, businesses may scale up or down
their infrastructure, effectively using their resources.
o Performance and dependability: Private clouds give businesses more
control over the infrastructure at the foundation, improving performance and
dependability.
o Compliance and Regulatory Requirements: Organizations may more
easily fulfill certain compliance and regulatory standards using the private
 cloud. It provides the freedom to put in place strong security measures,
follow data residency laws, and follow industry-specific norms.
o Hybrid Cloud Integration: Private cloud can be integrated with public cloud
services, forming a hybrid cloud infrastructure. This integration allows
organizations to leverage the benefits of both private and public clouds.

Advantages of Private Cloud

There are the following advantages of the Private Cloud -

o Private cloud provides a high level of security and privacy to the users.
o Private cloud offers better performance with improved speed and space
capacity.
o It allows the IT team to quickly allocate and deliver on-demand IT resources.
o The organization has full control over the cloud because it is managed by the
organization itself. So, there is no need for the organization to depends on
anybody.
o It is suitable for organizations that require a separate cloud for their personal
use and data security is the first priority.
o Customizable to meet specific business needs and compliance regulations.
o Higher reliability and uptime compared to public cloud environments.
o Seamless integration with existing on-premises systems and applications.
o Better compliance and governance capabilities for industry-specific
regulations.
o Enhanced flexibility in resource allocation and application deployment.

Disadvantages of Private Cloud

o Skilled people are required to manage and operate cloud services.
o Private cloud is accessible within the organization, so the area of operations
is limited.
o Private cloud is not suitable for organizations that have a high user base, and
organizations that do not have the prebuilt infrastructure, sufficient
manpower to maintain and manage the cloud.
 o Higher upfront costs and ongoing maintenance expenses.
o Scaling resources can be challenging compared to public or hybrid cloud
options.
o Relies on internal IT staff for management and troubleshooting.
o Slower deployment timelines and implementation compared to public cloud
solutions.
o Limited access to the latest advancements and innovations offered by public
cloud providers.
o Reduced flexibility and agility compared to public cloud options.
o Challenges in keeping up with hardware and software upgrades and
compatibility.
o Higher risks of technology becoming outdated and the need for regular
infrastructure updates.

Hybrid Cloud
Hybrid Cloud is a combination of the public cloud and the private cloud. we
can say:
Hybrid Cloud = Public Cloud + Private Cloud

Hybrid cloud is partially secure because the services which are running on
the public cloud can be accessed by anyone, while the services which are
running on a private cloud can be accessed only by the organization's users.
In a hybrid cloud setup, organizations can leverage the benefits of both
public and private clouds to create a flexible and scalable computing
environment. The public cloud portion allows using cloud services provided
by third-party providers, accessible over the Internet.

Example: Google Application Suite (Gmail, Google Apps, and Google Drive),
Office 365 (MS Office on the Web and One Drive), Amazon Web Services.

Characteristics of Hybrid Cloud

o Integration of Public and Private Clouds: Hybrid cloud seamlessly
integrates public and private clouds, allowing organizations to leverage both
advantages. It provides a unified platform where workloads and data can be
deployed and managed across both environments.
o Flexibility and Scalability: Hybrid cloud offers resource allocation and
scalability flexibility. Organizations can dynamically scale their infrastructure
by utilizing additional resources from the public cloud while maintaining
control over critical workloads on the private cloud.
o Enhanced Security and Control: Hybrid cloud allows organizations to
maintain higher security and control over their sensitive data and critical
applications. Private cloud components provide a secure and dedicated
environment, while public cloud resources can be used for non-sensitive
tasks, ensuring a balanced approach to data protection.
o Cost Optimization: Hybrid cloud enables organizations to optimize costs by
utilizing the cost-effective public cloud for non-sensitive workloads while
keeping mission-critical applications and data on the more cost-efficient
private cloud. This approach allows for efficient resource allocation and cost
management.
o Data and Application Portability: Organizations can move workloads and
data between public and private clouds as needed with a hybrid cloud. This
portability offers agility and the ability to adapt to changing business
requirements, ensuring optimal performance and responsiveness.
 o Compliance and Regulatory Compliance: Hybrid cloud helps
organizations address compliance and regulatory requirements more
effectively. Sensitive data and applications can be kept within the private
cloud, ensuring compliance with industry-specific regulations while leveraging
the public cloud for other non-sensitive operations.
o Disaster Recovery and Business Continuity: Hybrid cloud facilitates
robust disaster recovery and business continuity strategies. Organizations
can replicate critical data and applications between the private and public
clouds, ensuring redundancy and minimizing the risk of data loss or service
disruptions.

Advantages of Hybrid Cloud

There are the following advantages of Hybrid Cloud -

o Hybrid cloud is suitable for organizations that require more security than the
public cloud.
o Hybrid cloud helps you to deliver new products and services more quickly.
o Hybrid cloud provides an excellent way to reduce the risk.
o Hybrid cloud offers flexible resources because of the public cloud and secure
resources because of the private cloud.
o Hybrid facilitates seamless integration between on-premises infrastructure
and cloud environments.
o Hybrid provides greater control over sensitive data and compliance
requirements.
o Hybrid enables efficient workload distribution based on specific needs and
performance requirements.
o Hybrid offers cost optimization by allowing organizations to choose the most
suitable cloud platform for different workloads.
o Hybrid enhances business continuity and disaster recovery capabilities with
private and public cloud resources.
 o Hybrid supports hybrid cloud architecture, allowing applications and data to
be deployed across multiple cloud environments based on their unique
requirements.

Disadvantages of Hybrid Cloud

o In Hybrid Cloud, security feature is not as good as the private cloud.
o Managing a hybrid cloud is complex because it is difficult to manage more
than one type of deployment model.
o In the hybrid cloud, the reliability of the services depends on cloud service
providers.
o Potential challenges in data integration and ensuring seamless connectivity
between different cloud platforms.
o Higher costs due to the need for managing and integrating multiple cloud
environments.
o Increased complexity in data governance and compliance management
across different cloud providers.
o Dependency on stable and high-bandwidth internet connections for efficient
hybrid cloud operations.
o Potential compatibility issues between various cloud platforms and
applications.
o Risk of vendor lock-in and limited portability of applications and data across
different cloud providers.
o Requires skilled IT staff with expertise in managing hybrid cloud
environments.

Community Cloud
Community cloud allows systems and services to be accessible by a group of
several organizations to share the information between the organization and
a specific community. It is owned, managed, and operated by one or more
organizations in the community, a third party, or a combination of them.

In a community cloud setup, the participating organizations, which can be

from the same industry, government sector, or any other community,
collaborate to establish a shared cloud infrastructure. This infrastructure
allows them to access shared services, applications, and data relevant to
their community.

Example: Health Care community cloud

Characteristics of Community Cloud

o Shared Infrastructure: Community cloud provides a shared infrastructure
accessible to a specific community of organizations. The participating
organizations can leverage this common cloud infrastructure to meet their
shared computing needs and objectives.
o Community-specific Services: The community cloud provides resources,
apps, and services adapted to the participating organizations' demands.
These services are created to meet the community's specific requirements
and difficulties while promoting effective communication and information
exchange.
o Community Ownership and Management: The community cloud is
owned, managed, and operated by one or more organizations from the
community, a third party, or a combination of both. The involved
organizations have a say in the governance and decision-making procedures
to ensure that the cloud infrastructure meets their shared objectives.
o Enhanced Security and Compliance: Community cloud emphasizes
security and compliance measures relevant to the specific community. It
 allows for implementing robust security controls, access management, and
compliance frameworks that meet the community's regulatory requirements
and industry standards.
o Cost Sharing and Efficiency: Participating organizations in a community
cloud benefit from cost sharing. By sharing the infrastructure and resources,
the costs associated with establishing and maintaining the cloud environment
are distributed among the community members. This leads to cost efficiency
and reduced financial burden for individual organizations.
o Collaboration and Knowledge Sharing: The community cloud encourages
communication and information exchange amongst participating businesses.
It gives community members a forum for project collaboration, information
sharing, and resource exploitation. This encourages creativity, education, and
effectiveness within the neighborhood.
o Scalability and Flexibility: Community cloud enables organizations to
scale up or reduce their resources in response to demand. This allows the
community to adjust to shifting computing requirements and efficiently use
cloud resources as needed.

Advantages of Community Cloud

There are the following advantages of Community Cloud -

o Community cloud is cost-effective because the whole cloud is being shared

by several organizations or communities.
o Community cloud is suitable for organizations that want to have a
collaborative cloud with more security features than the public cloud.
o It provides better security than the public cloud.
o It provdes collaborative and distributive environment.
o Community cloud allows us to share cloud resources, infrastructure, and
other capabilities among various organizations.
o Offers customization options to meet the unique needs and requirements of
the community.
o Simplifies compliance with industry-specific regulations and standards
through shared security measures.
 o Provides scalability and flexibility, allowing organizations to scale resources
based on changing demands.
o Promotes efficient resource utilization, reducing wastage, and optimizing
performance within the community.
o Enables organizations to leverage shared expertise and experiences, leading
to improved decision-making and problem-solving.

Disadvantages of Community Cloud

o Community cloud is not a good choice for every organization.
o Security features are not as good as the private cloud.
o It is not suitable if there is no collaboration.
o The fixed amount of data storage and bandwidth is shared among all
community members.
o Challenges in ensuring consistent performance and availability when multiple
organizations share the same resources.
o Limited scalability options as the shared resources determine the community
cloud's capacity.
o Potential conflicts of interest among community members regarding resource
allocation and usage.
o Transparent governance and agreement frameworks are required to address
potential disputes and ensure fair resource distribution.
o Inadequate technical support and service level agreements (SLAs) compared
to private or public cloud options.

Multi-Cloud
Multi-cloud is a strategy in cloud computing where companies utilize more
than one cloud service provider or platform to meet their computing needs.
It involves distributing workloads, applications, and statistics throughout
numerous cloud environments consisting of public, private, and hybrid
clouds.

Adopting a multi-cloud approach allows businesses to have the ability to

select and leverage the most appropriate cloud services from different
providers based on their specific necessities. This allows them to harness
each provider's distinctive capabilities and services, mitigating the risk of
relying solely on one vendor while benefiting from competitive pricing
models. '

Examples: Amazon Web Services (AWS), Microsoft Azure, and Google Cloud
Platform (GCP).

Characteristics of Multi-cloud
o Multiple Cloud Providers: The key characteristic of multi-cloud is the
utilization of multiple cloud service providers. Organizations can leverage the
offerings of different providers, such as Amazon web services (AWS),
Microsoft Azure, Google Cloud Platform (GCP), and others, to access a huge
range of services and capabilities.
o Diversification and Risk Reduction: Thanks to multi-cloud, organizations
may distribute workloads, apps, and data across several cloud environments.
This diversification decreases the danger of vendor lock-in, and the effects of
any service interruptions or outages from a single cloud provider are
lessened.
o Flexibility and Vendor Independence: Businesses using multi-cloud can
choose the finest cloud services from various providers per their
requirements. This approach enables companies to leverage each provider's
unique benefits and avoids needing to depend solely on a single supplier for
all their cloud computing requirements.
o Optimisation of Services and Costs: Organisations may optimize their
services and costs by using a multi-cloud strategy and choosing the most
 affordable and appropriate cloud provider for each workload or application.
They can use specialized services from many sources to meet certain
demands, taking advantage of competitive pricing structures.
o Enhanced Reliability and Performance: Multi-cloud enhances reliability
and performance by utilizing multiple cloud environments. By utilizing the
infrastructure and resources of various providers, organizations can achieve
high availability, scalability, and enhanced performance for their applications
and services
o Data Sovereignty and Compliance: Multi-cloud allows organizations to
address data sovereignty and compliance requirements by choosing cloud
providers with data centers in specific regions or jurisdictions. It provides
flexibility in managing data residency and regulatory compliance obligations.
o Interoperability and Integration: Multi-cloud necessitates interoperability
and integration between different cloud platforms. Organizations must ensure
seamless data exchange, application compatibility, and integration of
services across the various cloud environments they utilize.

Advantages of Multi-Cloud:
There are the following advantages of multi-Cloud -

o It allows organizations to choose the most suitable cloud services from

different providers based on their specific requirements.
o Distributing workloads and data across multiple cloud environments
enhances reliability and ensures resilience in case of service disruptions or
downtime.
o By utilizing its providers, organizations can avoid dependency on a single
vendor and mitigate the risks associated with vendor lock-in.
o Organizations can optimize services and costs by selecting the most cost-
effective and suitable cloud provider for each workload or application.
o Leveraging the infrastructure and resources of different cloud providers
allows organizations to achieve high availability, scalability, and improved
performance.
 o It enables organizations to select cloud providers with data centers in specific
regions, addressing data sovereignty and compliance requirements.
o Access to specialized services and capabilities from different providers
promotes innovation and allows organizations to leverage the best-in-class
offerings in the market.
o Distributing workloads across multiple clouds reduces the risk of data loss or
service disruptions, providing enhanced disaster recovery capabilities.

Disadvantages of Multi-Cloud:
o Increased complexity in managing multiple cloud environments.
o Potential for higher costs due to multiple subscriptions and data transfer fees.
o Challenges in ensuring data governance and compliance across multiple
clouds.
o Integration difficulties and compatibility issues between different cloud
providers.
o Potential for increased management overhead and resource requirements.
o Risk of vendor dependencies and interoperability challenges.

Difference between public cloud, private cloud, hybrid cloud, and

community cloud -
The below table shows the difference between public cloud, private cloud,
hybrid cloud, and community cloud.

Parameter Public Cloud Private Cloud Hybrid Community Multi-Cloud

Cloud Cloud

Host Service Enterprise Enterprise Community Multiple cloud

provider (Third party) (Third party) (Third party) providers

Users General Selected Selected Community Multiple

public users users members organizations
Access Internet Internet, VPN Internet, Internet, VPN Internet, VPN
VPN

Owner Service Enterprise Enterprise Community Multiple

provider organizations

Cost Pay-per- Infrastructure Mixed Shared cost Variable

usage investment (variable) among depending on
members usage

Security Provider's Enhanced Varied Varied Varied

responsibility control (depends on (depends on (depends on
setup) setup) setup)

Scalability Highly Scalable Scalable Scalable within Scalable within

scalable within within resources resources
resources resources

Customizati Limited High control Varied Varied Varied

on control (depends on (depends on (depends on
setup) setup) setup)

Resource Not shared Not shared Varied Shared among Shared among
Sharing (depends on community providers
setup)

Public Cloud
o Public Cloud provides a shared platform that is accessible to the general
public through an Internet connection.
o Public cloud operated on the pay-as-per-use model and administrated by
the third party, i.e., Cloud service provider.
o In the Public cloud, the same storage is being used by multiple users at the
same time.
 o Public cloud is owned, managed, and operated by businesses, universities,
government organizations, or a combination of them.
o Amazon Elastic Compute Cloud (EC2), Microsoft Azure, IBM's Blue Cloud, Sun
Cloud, and Google Cloud are examples of the public cloud.

Advantages of Public Cloud

There are the following advantages of public cloud -

1) Low Cost

Public cloud has a lower cost than private, or hybrid cloud, as it shares the
same resources with a large number of consumers.

2) Location Independent

Public cloud is location independent because its services are offered through
the internet.

3) Save Time

In Public cloud, the cloud service provider is responsible for the manage and
maintain data centers in which data is stored, so the cloud user can save
their time to establish connectivity, deploying new products, release product
updates, configure, and assemble servers.
4) Quickly and easily set up

Organizations can easily buy public cloud on the internet and deployed and
configured it remotely through the cloud service provider within a few hours.

5) Business Agility

Public cloud provides an ability to elastically re-size computer resources

based on the organization's requirements.

6) Scalability and reliability

Public cloud offers scalable (easy to add and remove) and reliable (24*7
available) services to the users at an affordable cost.

Disadvantages of Public Cloud

1) Low Security

Public Cloud is less secure because resources are shared publicly.

2) Performance

In the public cloud, performance depends upon the speed of internet

connectivity.

3) Less customizable

Public cloud is less customizable than the private cloud.

Private Cloud
o Private cloud is also known as an internal cloud or corporate cloud.
o Private cloud provides computing services to a private internal network
(within the organization) and selected users instead of the general
public.
o Private cloud provides a high level of security and privacy to data through
firewalls and internal hosting. It also ensures that operational and sensitive
data are not accessible to third-party providers.
 o HP Data Centers, Microsoft, Elastra-private cloud, and Ubuntu are the
example of a private cloud.

Advantages of Private cloud

There are the following advantages of Private Cloud -

1) More Control

Private clouds have more control over their resources and hardware than
public clouds because it is only accessed by selected users.

2) Security & privacy

Security & privacy are one of the big advantages of cloud computing. Private
cloud improved the security level as compared to the public cloud.

3) Improved performance

Private cloud offers better performance with improved speed and space
capacity.
Disadvantages of Private Cloud
1) High cost

The cost is higher than a public cloud because set up and maintain hardware
resources are costly.

2) Restricted area of operations

As we know, private cloud is accessible within the organization, so the area

of operations is limited.

3) Limited scalability

Private clouds are scaled only within the capacity of internal hosted
resources.

4) Skilled people

Skilled people are required to manage and operate cloud services.

Hybrid Cloud
o Hybrid cloud is a combination of public and private clouds.
Hybrid cloud = public cloud + private cloud
o The main aim to combine these cloud (Public and Private) is to create a
unified, automated, and well-managed computing environment.
o In the Hybrid cloud, non-critical activities are performed by the public
cloud and critical activities are performed by the private cloud.
o Mainly, a hybrid cloud is used in finance, healthcare, and Universities.
o The best hybrid cloud provider companies are Amazon, Microsoft, Google,
Cisco, and NetApp.
Advantages of Hybrid Cloud
There are the following advantages of Hybrid Cloud -

1) Flexible and secure

It provides flexible resources because of the public cloud and secure

resources because of the private cloud.

2) Cost effective

Hybrid cloud costs less than the private cloud. It helps organizations to save
costs for both infrastructure and application support.

3) Cost effective

It offers the features of both the public as well as the private cloud. A hybrid
cloud is capable of adapting to the demands that each company needs for
space, memory, and system.

4) Security

Hybrid cloud is secure because critical activities are performed by the private
cloud.
5) Risk Management

Hybrid cloud provides an excellent way for companies to manage the risk.

Disadvantages of Hybrid Cloud

1) Networking issues

In the Hybrid Cloud, networking becomes complex because of the private

and the public cloud.

2) Infrastructure Compatibility

Infrastructure compatibility is the major issue in a hybrid cloud. With dual-

levels of infrastructure, a private cloud controls the company, and a public
cloud does not, so there is a possibility that they are running in separate
stacks.

3) Reliability

The reliability of the services depends on cloud service providers.

Community Cloud
Community cloud is a cloud infrastructure that allows systems and services
to be accessible by a group of several organizations to share the information.
It is owned, managed, and operated by one or more organizations in the
community, a third party, or a combination of them.
Example: Our government organization within India may share computing
infrastructure in the cloud to manage data.

Advantages of Community Cloud

There are the following advantages of Community Cloud -

Cost effective

Community cloud is cost effective because the whole cloud is shared

between several organizations or a community.

Flexible and Scalable

The community cloud is flexible and scalable because it is compatible with

every user. It allows the users to modify the documents as per their needs
and requirement.

Security

Community cloud is more secure than the public cloud but less secure than
the private cloud.
Sharing infrastructure

Community cloud allows us to share cloud resources, infrastructure, and

other capabilities among various organizations.

Disadvantages of Community Cloud

There are the following disadvantages of Community Cloud -

o Community cloud is not a good choice for every organization.

o Slow adoption to data
o The fixed amount of data storage and bandwidth is shared among all
community members.
o Community Cloud is costly than the public cloud.
o Sharing responsibilities among organizations is difficult.

1.11 Cloud Service Models

There are the following three types of cloud service models -

1. Infrastructure as a Service (IaaS)

2. Platform as a Service (PaaS)
3. Software as a Service (SaaS)
Infrastructure as a Service (IaaS)
IaaS is also known as Hardware as a Service (HaaS). It is a computing
infrastructure managed over the internet. The main advantage of using IaaS
is that it helps users to avoid the cost and complexity of purchasing and
managing the physical servers.

Characteristics of IaaS
There are the following characteristics of IaaS -

o Resources are available as a service

o Services are highly scalable
o Dynamic and flexible
o GUI and API-based access
o Automated administrative tasks

Example: DigitalOcean, Linode, Amazon Web Services (AWS), Microsoft

Azure, Google Compute Engine (GCE), Rackspace, and Cisco Metacloud.
Platform as a Service (PaaS)
PaaS cloud computing platform is created for the programmer to develop,
test, run, and manage the applications.

Characteristics of PaaS
There are the following characteristics of PaaS -

o Accessible to various users via the same development application.

o Integrates with web services and databases.
o Builds on virtualization technology, so resources can easily be scaled up or
down as per the organization's need.
o Support multiple languages and frameworks.
o Provides an ability to "Auto-scale".

Example: AWS Elastic Beanstalk, Windows Azure, Heroku, Force.com,

Google App Engine, Apache Stratos, Magento Commerce Cloud, and
OpenShift.

Software as a Service (SaaS)

SaaS is also known as "on-demand software". It is a software in which the
applications are hosted by a cloud service provider. Users can access these
applications with the help of internet connection and web browser.

Characteristics of SaaS
There are the following characteristics of SaaS -

o Managed from a central location

o Hosted on a remote server
o Accessible over the internet
o Users are not responsible for hardware and software updates. Updates are
applied automatically.
o The services are purchased on the pay-as-per-use basis
Example: BigCommerce, Google Apps, Salesforce, Dropbox, ZenDesk, Cisco
WebEx, ZenDesk, Slack, and GoToMeeting.

Difference between IaaS, PaaS, and SaaS

The below table shows the difference between IaaS, PaaS, and SaaS -

IaaS Paas SaaS

It provides a virtual data It provides virtual platforms It provides web software

center to store information and tools to create, test, and and apps to complete
and create platforms for deploy apps. business tasks.
app development, testing,
and deployment.

It provides access to It provides runtime It provides software as a

resources such as virtual environments and deployment service to the end-users.
machines, virtual storage, tools for applications.
etc.

It is used by network It is used by developers. It is used by end users.

architects.

IaaS provides only PaaS provides SaaS provides

Infrastructure. Infrastructure+Platform. Infrastructure+Platform
+Software.

Infrastructure as a Service | IaaS

Iaas is also known as Hardware as a Service (HaaS). It is one of the layers
of the cloud computing platform. It allows customers to outsource their IT
infrastructures such as servers, networking, processing, storage, virtual
machines, and other resources. Customers access these resources on the
Internet using a pay-as-per use model.

In traditional hosting services, IT infrastructure was rented out for a specific

period of time, with pre-determined hardware configuration. The client paid
for the configuration and time, regardless of the actual use. With the help of
the IaaS cloud computing platform layer, clients can dynamically scale the
configuration to meet changing requirements and are billed only for the
services actually used.

IaaS cloud computing platform layer eliminates the need for every
organization to maintain the IT infrastructure.

IaaS is offered in three models: public, private, and hybrid cloud. The private
cloud implies that the infrastructure resides at the customer-premise. In the
case of public cloud, it is located at the cloud computing platform vendor's
data center, and the hybrid cloud is a combination of the two in which the
customer selects the best of both public cloud or private cloud.

IaaS provider provides the following services -

1. Compute: Computing as a Service includes virtual central processing units

and virtual main memory for the Vms that is provisioned to the end- users.
2. Storage: IaaS provider provides back-end storage for storing files.
3. Network: Network as a Service (NaaS) provides networking components
such as routers, switches, and bridges for the Vms.
4. Load balancers: It provides load balancing capability at the infrastructure
layer.
Advantages of IaaS cloud computing layer
There are the following advantages of IaaS computing layer -

1. Shared infrastructure

IaaS allows multiple users to share the same physical infrastructure.

2. Web access to the resources

Iaas allows IT users to access resources over the internet.

3. Pay-as-per-use model

IaaS providers provide services based on the pay-as-per-use basis. The users
are required to pay for what they have used.

4. Focus on the core business

IaaS providers focus on the organization's core business rather than on IT

infrastructure.

5. On-demand scalability

On-demand scalability is one of the biggest advantages of IaaS. Using IaaS,

users do not worry about to upgrade software and troubleshoot the issues
related to hardware components.

Disadvantages of IaaS cloud computing layer

1. Security

Security is one of the biggest issues in IaaS. Most of the IaaS providers are
not able to provide 100% security.

2. Maintenance & Upgrade

Although IaaS service providers maintain the software, but they do not
upgrade the software for some organizations.

3. Interoperability issues

It is difficult to migrate VM from one IaaS provider to the other, so the

customers might face problem related to vendor lock-in.
Some important point about IaaS cloud computing layer
IaaS cloud computing platform cannot replace the traditional hosting
method, but it provides more than that, and each resource which are used
are predictable as per the usage.

IaaS cloud computing platform may not eliminate the need for an in-house IT
department. It will be needed to monitor or control the IaaS setup. IT salary
expenditure might not reduce significantly, but other IT expenses can be
reduced.

Breakdowns at the IaaS cloud computing platform vendor's can bring your
business to the halt stage. Assess the IaaS cloud computing platform
vendor's stability and finances. Make sure that SLAs (i.e., Service Level
Agreement) provide backups for data, hardware, network, and application
failures. Image portability and third-party support is a plus point.

The IaaS cloud computing platform vendor can get access to your sensitive
data. So, engage with credible companies or organizations. Study their
security policies and precautions.

Top Iaas Providers who are providing IaaS cloud computing

platform
IaaS Vendor Iaas Solution Details

Amazon Web Services Elastic, Elastic Compute The cloud computing platform
Cloud (EC2) MapReduce, pioneer, Amazon offers auto scaling,
Route 53, Virtual Private cloud monitoring, and load
Cloud, etc. balancing features as part of its
portfolio.

Netmagic Solutions Netmagic IaaS Cloud Netmagic runs from data centers in
Mumbai, Chennai, and Bangalore,
and a virtual data center in the
United States. Plans are underway
to extend services to West Asia.

Rackspace Cloud servers, cloud files, The cloud computing platform

cloud sites, etc. vendor focuses primarily on
enterprise-level hosting services.

Reliance Reliance Internet Data RIDC supports both traditional

Communications Center hosting and cloud services, with
data centers in Mumbai, Bangalore,
Hyderabad, and Chennai. The cloud
services offered by RIDC include
IaaS and SaaS.

Sify Technologies Sify IaaS Sify's cloud computing platform is

powered by HP's converged
infrastructure. The vendor offers all
three types of cloud services: IaaS,
PaaS, and SaaS.

Tata Communications InstaCompute InstaCompute is Tata

Communications' IaaS offering.
InstaCompute data centers are
located in Hyderabad and
Singapore, with operations in both
countries.
Platform as a Service | PaaS
Platform as a Service (PaaS) provides a runtime environment. It allows
programmers to easily create, test, run, and deploy web applications. You
can purchase these applications from a cloud service provider on a pay-as-
per use basis and access them using the Internet connection. In PaaS, back
end scalability is managed by the cloud service provider, so end- users do
not need to worry about managing the infrastructure.

PaaS includes infrastructure (servers, storage, and networking) and platform

(middleware, development tools, database management systems, business
intelligence, and more) to support the web application life cycle.

Example: Google App Engine, Force.com, Joyent, Azure.

PaaS providers provide the Programming languages, Application frameworks,

Databases, and Other tools:

1. Programming languages
PaaS providers provide various programming languages for the developers
to develop the applications. Some popular programming languages provided
by PaaS providers are Java, PHP, Ruby, Perl, and Go.
2. Application frameworks
PaaS providers provide application frameworks to easily understand the
application development. Some popular application frameworks provided by
PaaS providers are Node.js, Drupal, Joomla, WordPress, Spring, Play, Rack,
and Zend.

3. Databases
PaaS providers provide various databases such as ClearDB, PostgreSQL,
MongoDB, and Redis to communicate with the applications.

4. Other tools
PaaS providers provide various other tools that are required to develop, test,
and deploy the applications.

Advantages of PaaS
There are the following advantages of PaaS -

1) Simplified Development

PaaS allows developers to focus on development and innovation without

worrying about infrastructure management.

2) Lower risk

No need for up-front investment in hardware and software. Developers only

need a PC and an internet connection to start building applications.

3) Prebuilt business functionality

Some PaaS vendors also provide already defined business functionality so

that users can avoid building everything from very scratch and hence can
directly start the projects only.

4) Instant community

PaaS vendors frequently provide online communities where the developer

can get the ideas to share experiences and seek advice from others.

5) Scalability
Applications deployed can scale from one to thousands of users without any
changes to the applications.

Disadvantages of PaaS cloud computing layer

1) Vendor lock-in

One has to write the applications according to the platform provided by the
PaaS vendor, so the migration of an application to another PaaS vendor
would be a problem.

2) Data Privacy

Corporate data, whether it can be critical or not, will be private, so if it is not

located within the walls of the company, there can be a risk in terms of
privacy of data.

3) Integration with the rest of the systems applications

It may happen that some applications are local, and some are in the cloud.
So there will be chances of increased complexity when we want to use data
which in the cloud with the local data.
Popular PaaS Providers

The below table shows some popular PaaS providers and services that are
provided by them -

Providers Services

Google App App Identity, URL Fetch, Cloud storage client library, Logservice
Engine
(GAE)

Salesforce.c Faster implementation, Rapid scalability, CRM Services, Sales

om cloud, Mobile connectivity, Chatter.

Windows Compute, security, IoT, Data Storage.

Azure

AppFog Justcloud.com, SkyDrive, GoogleDocs

 Openshift RedHat, Microsoft Azure.

Cloud Data, Messaging, and other services.

Foundry
from
VMware

Software as a Service | SaaS

SaaS is also known as "On-Demand Software". It is a software distribution
model in which services are hosted by a cloud service provider. These
services are available to end-users over the internet so, the end-users do not
need to install any software on their devices to access these services.

There are the following services provided by SaaS providers -

Business Services - SaaS Provider provides various business services to

start-up the business. The SaaS business services include ERP (Enterprise
Resource Planning), CRM (Customer Relationship Management), billing,
and sales.

Document Management - SaaS document management is a software

application offered by a third party (SaaS providers) to create, manage, and
track electronic documents.

Example: Slack, Samepage, Box, and Zoho Forms.

Social Networks - As we all know, social networking sites are used by the
general public, so social networking service providers use SaaS for their
convenience and handle the general public's information.

Mail Services - To handle the unpredictable number of users and load on e-

mail services, many e-mail providers offering their services using SaaS.
Advantages of SaaS cloud computing layer
1) SaaS is easy to buy

SaaS pricing is based on a monthly fee or annual fee subscription, so it

allows organizations to access business functionality at a low cost, which is
less than licensed applications.

Unlike traditional software, which is sold as a licensed based with an up-front

cost (and often an optional ongoing support fee), SaaS providers are
generally pricing the applications using a subscription fee, most commonly a
monthly or annually fee.

2. One to Many

SaaS services are offered as a one-to-many model means a single instance

of the application is shared by multiple users.

3. Less hardware required for SaaS

The software is hosted remotely, so organizations do not need to invest in

additional hardware.

4. Low maintenance required for SaaS

Software as a service removes the need for installation, set-up, and daily
maintenance for the organizations. The initial set-up cost for SaaS is typically
less than the enterprise software. SaaS vendors are pricing their applications
based on some usage parameters, such as a number of users using the
application. So SaaS does easy to monitor and automatic updates.

5. No special software or hardware versions required

All users will have the same version of the software and typically access it
through the web browser. SaaS reduces IT support costs by outsourcing
hardware and software maintenance and support to the IaaS provider.

6. Multidevice support

SaaS services can be accessed from any device such as desktops, laptops,
tablets, phones, and thin clients.

7. API Integration

SaaS services easily integrate with other software or services through

standard APIs.

8. No client-side installation

SaaS services are accessed directly from the service provider using the
internet connection, so do not need to require any software installation.

Disadvantages of SaaS cloud computing layer

1) Security

Actually, data is stored in the cloud, so security may be an issue for some
users. However, cloud computing is not more secure than in-house
deployment.

2) Latency issue

Since data and applications are stored in the cloud at a variable distance
from the end-user, there is a possibility that there may be greater latency
when interacting with the application compared to local deployment.
Therefore, the SaaS model is not suitable for applications whose demand
response time is in milliseconds.

3) Total Dependency on Internet

Without an internet connection, most SaaS applications are not usable.

4) Switching between SaaS vendors is difficult

Switching SaaS vendors involves the difficult and slow task of transferring
the very large data files over the internet and then converting and importing
them into another SaaS also.

Popular SaaS Providers

The below table shows some popular SaaS providers and services that are
provided by them -

Provider Services

Salseforce.c On-demand CRM solutions

om
Microsoft Online office suite
Office 365

Google Apps Gmail, Google Calendar, Docs, and sites

NetSuite ERP, accounting, order management, CRM, Professionals Services

Automation (PSA), and e-commerce applications.

GoToMeetin Online meeting and video-conferencing software

g

Constant E-mail marketing, online survey, and event marketing

Contact

Oracle CRM CRM applications

Workday, Inc Human capital management, payroll, and financial management.

1.12 Difference between Cloud

Computing and Traditional Computing
1. Cloud Computing :
Cloud Computing, as name suggests, is collective combination of
configurable system resources and advanced service that can be
delivered quickly using internet. It simply provides lower power
expenses, no capital costs, no redundancy, lower employee costs,
increased collaboration, etc. It makes us more efficient, more secure,
and provide greater flexibility.
Advantages of Cloud Computing :
 Scalability: Cloud computing allows organizations to easily scale
their computing resources up or down as their needs change,
without having to purchase and manage additional hardware.
 Cost Savings: Using cloud computing can be more cost-effective
than maintaining on-premises IT infrastructure, as it eliminates the
need for costly hardware, software, and maintenance expenses.
 Accessibility: Cloud computing enables remote access to
applications and data, allowing users to work from anywhere with
an internet connection.
 Reliability: Cloud providers offer high levels of uptime and
redundancy, ensuring that applications and data are available even
in the event of hardware failure.
 Flexibility: Cloud computing offers a wide range of deployment
options, including public, private, and hybrid clouds, which can be
tailored to meet the unique needs of an organization.
Disadvantages of Cloud Computing :
 Security: Cloud computing involves sharing sensitive data with a
third-party provider, which raises concerns about data security and
privacy.
 Dependence: Organizations that rely on cloud providers for their
computing infrastructure are vulnerable to service disruptions or
data loss in the event of provider outages or other issues.
 Internet Dependency: Cloud computing requires a reliable and
fast internet connection to access applications and data, which can
be a challenge in some areas.
 Technical Issues: Technical issues with cloud services, such as
compatibility problems or software bugs, can sometimes be
difficult to resolve and can result in downtime or lost productivity.
 Lack of Control: With cloud computing, organizations have
limited control over the infrastructure and services they use, which
can make it difficult to customize or optimize the environment for
their specific needs.
2. Traditional Computing :
Traditional Computing, as name suggests, is a possess of using
physical data centers for storing digital assets and running complete
networking system for daily operations. In this, access to data, or
software, or storage by users is limited to device or official network
they are connected with. In this computing, user can have access to
data only on system in which data is stored.
Advantages of Traditional Computing :
 Control: With traditional computing, an organization has full
control over the hardware and software it uses, allowing for
customization and optimization of the computing environment.
 Security: Traditional computing offers a high level of data
security, as sensitive data can be stored on-premises and
protected by firewalls, encryption, and other security measures.
 Reliability: Traditional computing is not dependent on internet
connectivity, making it less vulnerable to service disruptions or
data loss.
 Compatibility: Traditional computing environments can be
tailored to meet the specific needs of an organization, ensuring
compatibility with existing software and systems.
 Data Ownership: With traditional computing, an organization
owns and controls all of its data, reducing concerns about data
privacy and regulatory compliance.

Disadvantages of Traditional Computing :

 Cost: Traditional computing can be more expensive than cloud
computing, as it requires significant capital expenditures for
hardware and software, as well as ongoing maintenance and
support expenses.
 Scalability: Traditional computing can be difficult to scale up or
down to meet changing needs, as it requires additional hardware or
software to be added to the environment.
 Accessibility: Traditional computing may not allow for remote
access to applications and data, limiting the ability of users to work
from anywhere.
 Maintenance: Traditional computing environments require
ongoing maintenance and upgrades to ensure security and
performance, which can be time-consuming and expensive.
 Limited Storage Capacity: Traditional computing environments
may have limited storage capacity, requiring organizations to
periodically purchase additional hardware to accommodate
growing data volumes.

Difference between Cloud Computing and Traditional

Computing :
Cloud Computing Traditional Computing

It refers to delivery of different

services such as data and It refers to delivery of different
programs through internet on services on local server.
different servers.

It takes place on third-party

It takes place on physical hard drives
servers that is hosted by third-
and website servers.
party hosting companies.
 Cloud Computing Traditional Computing

It is ability to access data User can access data only on system

anywhere at any time by user. in which data is stored.

It is more cost effective as

compared to tradition computing It is less cost effective as compared
as operation and maintenance of to cloud computing because one has
server is shared among several to buy expensive equipment’s to
parties that in turn reduce cost operate and maintain server.
of public services.

It is less user-friendly as compared to

It is more user-friendly as
cloud computing because data
compared to traditional
cannot be accessed anywhere and if
computing because user can
user has to access data in another
have access to data anytime
system, then he need to save it in
anywhere using internet.
external storage medium.

It requires fast, reliable and

It does not require any internet
stable internet connection to
connection to access data or
access information anywhere at
information.
any time.

It provides more storage space

and servers as well as more
It provides less storage as compared
computing power so that
to cloud computing.
applications and software run
must faster and effectively.

It also provides scalability and

elasticity i.e., one can increase
It does not provide any scalability
or decrease storage capacity,
and elasticity.
server resources, etc., according
to business needs.

It requires own team to maintain and

Cloud service is served by
monitor system that will need a lot of
provider’s support team.
time and efforts.
 Cloud Computing Traditional Computing

Software is offered as an on-

Software in purchased individually for
demand service (SaaS) that can
every user and requires to be
be accessed through
updated periodically.
subscription service.

1.13 Five Benefits of Cloud Computing

1. Long-term cost savings

Cost reduction is a top benefit of cloud education software.

Compared to managing an on-premise data center, cloud migration

supports an IT ecosystem by helping companies shift from capital
expenses to predictable monthly operating expenses.

These predictable monthly expenses bring several benefits to

institutions, including:

 Reduced data storage costs

 Minimal data center maintenance
 Less money spent on replacing aging physical IT hardware
This is a cost-effective way to enhance your learning environment
and create new educational opportunities.

2. Better collaboration

Real-time collaboration is an important aspect of cloud computing

education. Cloud software helps to:

 Support student communication

 Create teacher management portals
 Power remote learning virtual classrooms
Cloud management in education creates plenty of new collaborative
possibilities. It’s the easiest way to create an environment where
educators, students, and parents can stay on the same page.

3. Easy access and resource availability

A cloud-based education platform also improves physical and digital

access to resources. It makes it easier for students to access the
same materials and learning resources, regardless of the devices or
internet browsers they use.

Virtual solutions like cloud computing also provide ongoing learning

opportunities for all students. They are often implemented in
accordance with the Web Content Accessibility Guidelines (WCAG).

The WCAG is a list of recommendations that improve the

accessibility of web-based content for people with disabilities and
across mobile platforms.

WCAG-compliant online learning ensures that students with mobility

issues or learning impairments can receive personalized
instructional programs that properly address their needs.

4. Scalability

Compared with scaling on-premise data centers, cloud-based

software helps to reduce costs associated with facility growth.

No matter how many students you have or higher education

facilities you manage, your cloud system can grow alongside you.

5. Modernizing learning environments

Solutions like the VMware cloud for education, available through

Microsoft DaaS, are the best way to prepare educational institutions
for the future. These technologies make your school more desirable
for incoming students and allow you to provide a higher standard of
learning.
5 challenges of cloud computing
Despite its benefits, there are also a few cloud computing issues and
challenges in education.

1. Dependence on internet service providers

An unfortunate reality of cloud computing in education is its reliance

on internet access. Unlike traditional classrooms, service outages or
poor bandwidth experienced by internet service providers can
detract from online learning.

Unless you are working with a managed IT service provider, it can

be difficult to quickly determine whether the source of the issue is
the end user or the internet provider.

2. Less control

Although a benefit of cloud is accessibility to services and platforms

in the education sector (like Blackboard), the concern is you have
less control over updates, training, and other features.
Since the solution is being handled “as a service,” the infrastructure
is handled by the cloud service provider and abstracted from your
in-house team.

Everything is hosted off-site, so you’ll have less control over the

infrastructure and the system setup. These are handled by your
cloud service provider.

3. Vendor commitment

Cloud solutions for higher education depend on the services of a

single vendor. Because you typically can’t switch between service
providers, it is critical to pick the right provider when moving the
educational workload to the cloud.
A good provider listens to you, understands your risk, and manages
it from beginning to end, eliminating any unforeseen issues that
may occur.

In most cases, once you sign with a provider, you will be locked into
a service contract with them. However, most providers will let you
out of a contract but will charge you a penalty for breaking the
contract early. This may not be a problem if you’re satisfied with
your services, but it’s worth mentioning all the same.

4. Security

Cloud-based education technology is secure when set up correctly,

but there are inherent security risks when all assets are hosted
online. Improperly secured cloud systems may be vulnerable to
cyberattacks, and data security becomes a bigger concern.

This concern escalates when users access resources across devices.

If a device with saved credentials gets stolen, the cloud platform
becomes accessible to an unauthorized user.

To avoid these issues, you’ll need to make security a priority. This

begins with a proper setup of your cloud infrastructure and ensuring
that all users are trained in cloud security best practices.

For example, considering an MDM management or multi-factor

authentication measures would offset many security concerns. This
would also provide more protection from end user device
vulnerability.

5. Up-front costs

While cost reduction is one of the primary benefits of cloud

computing in education, there are also some up-front costs.

The migration may be costly, depending on how many applications

or services you’re moving to the cloud. There’s also an opportunity
cost in the time required to train staff on the new system and
security best practices.
The savings come more from long-term reductions in operational IT
costs, but administrators will need to be prepared for the long-term
savings it will yield.

1.14 Introduction to Amazon Web

Services
Amazon Web Services (AWS), a subsidiary of Amazon.com, has
invested billions of dollars in IT resources distributed across the globe.
These resources are shared among all the AWS account holders
across the globe. These account themselves are entirely isolated from
each other. AWS provides on-demand IT resources to its account
holders on a pay-as-you-go pricing model with no upfront cost.
Amazon Web services offers flexibility because you can only pay for
services you use or you need. Enterprises use AWS to reduce capital
expenditure of building their own private IT infrastructure (which can
be expensive depending upon the enterprise’s size and nature). AWS
has its own Physical fiber network that connects with Availability
zones, regions and Edge locations. All the maintenance cost is also
taken care by the AWS which saves a fortune for the enterprises.
Security of the cloud is the responsibility of AWS but Security in the
cloud is the Customer’s Responsibility. The Performance efficiency in
the cloud has four main areas:-
 Selection
 Review
 Monitoring
 Tradeoff
Advantages of Amazon Web Services
 AWS allows you to easily scale your resources up or down as your
needs change, helping you to save money and ensure that your
application always has the resources it needs.
 AWS provides a highly reliable and secure infrastructure, with
multiple data centers and a commitment to 99.99% availability for
many of its services.
 AWS offers a wide range of services and tools that can be easily
combined to build and deploy a variety of applications, making it
highly flexible.
 AWS offers a pay-as-you-go pricing model, allowing you to only
pay for the resources you actually use and avoid upfront costs and
long-term commitments.
Disadvantages of Amazon Web Services
 AWS can be complex, with a wide range of services and features
that may be difficult to understand and use, especially for new
users.
 AWS can be expensive, especially if you have a high-traffic
application or need to run multiple services. Additionally, the cost
of services can increase over time, so you need to regularly
monitor your spending.
 While AWS provides many security features and tools, securing
your resources on AWS can still be challenging, and you may need
to implement additional security measures to meet your specific
requirements.
 AWS manages many aspects of the infrastructure, which can limit
your control over certain parts of your application and
environment.
AWS Global Infrastructure
The AWS global infrastructure is massive and is divided into
geographical regions. The geographical regions are then divided into
separate availability zones. While selecting the geographical regions
for AWS, three factors come into play
 Optimizing Latency
 Reducing cost
 Government regulations (Some services are not available for some
regions)
Each region is divided into at least two availability zones that are
physically isolated from each other, which provides business
continuity for the infrastructure as in a distributed system. If one zone
fails to function, the infrastructure in other availability zones remains
operational. The largest region North Virginia (US-East), has six
availability zones. These availability zones are connected by high-
speed fiber-optic networking.
There are over 100 edge locations distributed all over the globe that
are used for the CloudFront (content delivery
network). CloudFront can cache frequently used content such as
images and videos(live streaming videos also) at edge locations and
distribute it to edge locations across the globe for high-speed delivery
and low latency for end-users. It also protects from DDOS attacks.
AWS Management Console
The AWS management console is a web-based interface to access
AWS. It requires an AWS account and also has a smartphone
application for the same purpose. So When you sign in for first time,
you see the console home page where you see all the services
provided by AWS. Cost monitoring is also done through the console.
AWS resources can also be accessed through various Software
Development Kits (SDKs), which allows the developers to create
applications as AWS as its backend. There are SDKs for all the major
languages(e.g., JavaScript, Python, Node.js, .Net, PHP, Ruby, Go, C+
+). There are mobile SDKs for Android, iOS, React Native, Unity, and
Xamarin. AWS can also be accessed by making HTTP calls using the
AWS-API. AWS also provides a Command Line Interface (CLI) for
remotely accessing the AWS and can implement scripts to automate
many processes. This Console is also available as an app for Android
and iOS. For mobile apps, you can simply download AWS console
app.
AWS Cloud Computing Models
There are three cloud computing models available on AWS.
1. Infrastructure as a Service (IaaS): It is the basic building block of
cloud IT. It generally provides access to data storage space,
networking features, and computer hardware(virtual or dedicated
hardware). It is highly flexible and gives management controls over
the IT resources to the developer. For example, VPC, EC2, EBS.

2. Platform as a Service (PaaS): This is a type of service where AWS

manages the underlying infrastructure (usually operating system
and hardware). This helps the developer to be more efficient as
they do not have to worry about undifferentiated heavy lifting
required for running the applications such as capacity planning,
software maintenance, resource procurement, patching, etc., and focus
more on deployment and management of the applications. For
example, RDS, EMR, ElasticSearch.

3. Software as a Service(SaaS): It is a complete product that usually runs on a

browser. It primarily refers to end-user applications. It is run and managed
by the service provider. The end-user only has to worry about the application
of the software suitable to its needs. For example, Saleforce.com, Web-
based email, Office 365 .