Software

Software, which is abbreviated as SW or S/W, is a set of programs that enables the hardware to
perform a specific task. All the programs that run the computer are software. The software can be
of three types: system software, application software, and programming software.
1) System Software
The system software is the main software that runs the computer. When you turn on the
computer, it activates the hardware and controls and coordinates their functioning. The
application programs are also controlled by system software. An operating system is an example
of system software.
i) Operating System:
An operating system is the system software that works as an interface to enable the user to
communicate with the computer. It manages and coordinates the functioning of hardware and
software of the computer. The commonly used operating systems are Microsoft
Windows, Linux, and Apple Mac OS X.
Some other examples of system software include:
o BIOS: It stands for basic input output system. It is a type of system software, which is stored in
Read Only Memory (ROM) located on the motherboard. However, in advanced computer
systems, it is stored in flash memory. BIOS is the first software that gets activated when you turn
on your computer system. It loads the drivers of the hard disk into memory as well as assists the
operating system to load itself into the memory.
o Boot Program: Boot refers to starting up a computer. When you switch on the computer, the
commands in the ROM are executed automatically to load the boot program into memory and
execute its instructions. The BIOS program has a basic set of commands that enables the
computer to perform the basic input/output instructions to start the computer.
o An assembler: It plays the role of a converter as it receives basic computer instructions and
converts them into a pattern of bits. The processor uses these bits to perform basic operations.
o A device driver: This system software controls hardware devices connected to a computer. It
enables the computer to use the hardware by providing an appropriate interface. The kernel of a
Computer's CPU communicates with different hardware through this software. Operating systems
generally come with most of the device drivers. If the operating system does not have a device
driver for hardware, you have to install the device driver before using that hardware device.
2) Application Software:
Application software is a set of programs designed to perform a specific task. It does not control
the working of a computer as it is designed for end-users. A computer can run without
application software. Application software can be easily installed or uninstalled as required. It
can be a single program or a collection of small programs. Microsoft Office Suite, Adobe
Photoshop, and any other software like payroll software or income tax software are application
software. As we know, they are designed to perform specific tasks. Accordingly, they can be of
different types such as:
o Word Processing Software: This software allows users to create, edit, format, and manipulate
the text and more. It offers lots of options for writing documents, creating images, and more. For
example, MS Word, WordPad, Notepad, etc.
o Spreadsheet Software: It is designed to perform calculations, store data, create charts, etc. It has
rows and columns, and the data is entered in the cell, which is an intersection of a row and
column, e.g., Microsoft Excel.
o Multimedia Software: These software are developed to perform editing of video, audio, and
text. It allows you to combine texts, videos, audio, and images. Thus, you can improve a text
document by adding photos, animations, graphics, and charts through multimedia software. For
example, VLC player, Window Media Player, etc.
o Enterprise Software: These software are developed for business operational functions. It is used
in large organizations where the quantum of business is too large. It can be used for accounting,
billing, order processing and more. For example, CRM (Customer Relationship Management), BI
(Business Intelligence), ERP (Enterprise Resource Planning), SCM (Supply Chain Management),
customer support system, and more.
3) Programming Software:
It is a set or collection of tools that help developers in writing other software or programs. It
assists them in creating, debugging, and maintaining software or programs or applications. We
can say that these are facilitator software that helps translate programming language such
as Java, C++, Python, etc., into machine language code. So, it is not used by end-users. For
example, compilers, linkers, debuggers, interpreters, text editors, etc. This software is also called
a programming tool or software development tool.
Some examples of programming software include:
o Eclipse: It is a java language editor.
o Coda: It is a programming language editor for Mac.
o Notepad++: It is an open-source editor for windows.
o Sublime text: It is a cross-platform code editor for Linux, Mac, and Windows.

Computer Network
Computer Network tutorial provides basic and advanced concepts of Data Communication &
Networks (DCN). Our Computer Networking Tutorial is designed for beginners and
professionals.
Our Computer Network tutorial includes all topics of Computer Network such as introduction,
features, types of computer network, architecture, hardware, software, internet, intranet, website,
LAN, WAN, etc.
What is Computer Network?
A computer network is a set of devices connected through links. A node can be computer,
printer, or any other device capable of sending or receiving the data. The links connecting the
nodes are known as communication channels.
Computer Network uses distributed processing in which task is divided among several
computers. Instead, a single computer handles an entire task, each separate computer handles a
subset.
Following are the advantages of Distributed processing:
o Security: It provides limited interaction that a user can have with the entire system. For
example, a bank allows the users to access their own accounts through an ATM without
allowing them to access the bank's entire database.
o Faster problem solving: Multiple computers can solve the problem faster than a single
machine working alone.
o Security through redundancy: Multiple computers running the same program at the
same time can provide the security through redundancy. For example, if four computers
run the same program and any computer has a hardware error, then other computers can
override it.
Computer Network Types
A computer network is a group of computers linked to each other that enables the computer to
communicate with another computer and share their resources, data, and applications.
A computer network can be categorized by their size. A computer network is mainly of four
types:

o LAN(Local Area Network)

o PAN(Personal Area Network)
o MAN(Metropolitan Area Network)
o WAN(Wide Area Network)

LAN(Local Area Network)

o Local Area Network is a group of computers connected to each other in a small area such
as building, office.
 o LAN is used for connecting two or more personal computers through a communication
medium such as twisted pair, coaxial cable, etc.
o It is less costly as it is built with inexpensive hardware such as hubs, network adapters,
and ethernet cables.
o The data is transferred at an extremely faster rate in Local Area Network.
o Local Area Network provides higher security.

PAN(Personal Area Network)

o Personal Area Network is a network arranged within an individual person, typically
within a range of 10 meters.
o Personal Area Network is used for connecting the computer devices of personal use is
known as Personal Area Network.
o Thomas Zimmerman was the first research scientist to bring the idea of the Personal
Area Network.
o Personal Area Network covers an area of 30 feet.
o Personal computer devices that are used to develop the personal area network are the
laptop, mobile phones, media player and play stations.
There are two types of Personal Area Network:

o Wired Personal Area Network

o Wireless Personal Area Network
Wireless Personal Area Network: Wireless Personal Area Network is developed by simply
using wireless technologies such as WiFi, Bluetooth. It is a low range network.
Wired Personal Area Network: Wired Personal Area Network is created by using the USB.
Examples Of Personal Area Network:
o Body Area Network: Body Area Network is a network that moves with a person. For
example, a mobile network moves with a person. Suppose a person establishes a network
connection and then creates a connection with another device to share the information.
o Offline Network: An offline network can be created inside the home, so it is also known
as a home network. A home network is designed to integrate the devices such as
printers, computer, television but they are not connected to the internet.
 o Small Home Office: It is used to connect a variety of devices to the internet and to a
corporate network using a VPN

MAN(Metropolitan Area Network)

o A metropolitan area network is a network that covers a larger geographic area by
interconnecting a different LAN to form a larger network.
o Government agencies use MAN to connect to the citizens and private industries.
o In MAN, various LANs are connected to each other through a telephone exchange line.
o The most widely used protocols in MAN are RS-232, Frame Relay, ATM, ISDN, OC-3,
ADSL, etc.
o It has a higher range than Local Area Network(LAN).

Uses Of Metropolitan Area Network:

o MAN is used in communication between the banks in a city.
o It can be used in an Airline Reservation.
o It can be used in a college within a city.
o It can also be used for communication in the military.

WAN(Wide Area Network)

 o A Wide Area Network is a network that extends over a large geographical area such as
states or countries.
o A Wide Area Network is quite bigger network than the LAN.
o A Wide Area Network is not limited to a single location, but it spans over a large
geographical area through a telephone line, fibre optic cable or satellite links.
o The internet is one of the biggest WAN in the world.
o A Wide Area Network is widely used in the field of Business, government, and
education.

Examples Of Wide Area Network:

o Mobile Broadband: A 4G network is widely used across a region or country.
o Last mile: A telecom company is used to provide the internet services to the customers
in hundreds of cities by connecting their home with fiber.
o Private network: A bank provides a private network that connects the 44 offices. This
network is made by using the telephone leased line provided by the telecom company.
Advantages Of Wide Area Network:
Following are the advantages of the Wide Area Network:
o Geographical area: A Wide Area Network provides a large geographical area. Suppose
if the branch of our office is in a different city then we can connect with them through
WAN. The internet provides a leased line through which we can connect with another
branch.
 o Centralized data: In case of WAN network, data is centralized. Therefore, we do not
need to buy the emails, files or back up servers.
o Get updated files: Software companies work on the live server. Therefore, the
programmers get the updated files within seconds.
o Exchange messages: In a WAN network, messages are transmitted fast. The web
application like Facebook, Whatsapp, Skype allows you to communicate with friends.
o Sharing of software and resources: In WAN network, we can share the software and
other resources like a hard drive, RAM.
o Global business: We can do the business over the internet globally.
o High bandwidth: If we use the leased lines for our company then this gives the high
bandwidth. The high bandwidth increases the data transfer rate which in turn increases
the productivity of our company.
Disadvantages of Wide Area Network:
The following are the disadvantages of the Wide Area Network:
o Security issue: A WAN network has more security issues as compared to LAN and
MAN network as all the technologies are combined together that creates the security
problem.
o Needs Firewall & antivirus software: The data is transferred on the internet which can
be changed or hacked by the hackers, so the firewall needs to be used. Some people can
inject the virus in our system so antivirus is needed to protect from such a virus.
o High Setup cost: An installation cost of the WAN network is high as it involves the
purchasing of routers, switches.
o Troubleshooting problems: It covers a large area so fixing the problem is difficult.

Internetwork
o An internetwork is defined as two or more computer network LANs or WAN or
computer network segments are connected using devices, and they are configured by a
local addressing scheme. This process is known as internetworking.
o An interconnection between public, private, commercial, industrial, or government
computer networks can also be defined as internetworking.
o An internetworking uses the internet protocol.
o The reference model used for internetworking is Open System Interconnection(OSI).
Types Of Internetwork:
1. Extranet: An extranet is a communication network based on the internet protocol such
as Transmission Control protocol and internet protocol. It is used for information sharing.
The access to the extranet is restricted to only those users who have login credentials. An
extranet is the lowest level of internetworking. It can be categorized as MAN, WAN or other
computer networks. An extranet cannot have a single LAN, atleast it must have one connection
to the external network.
2. Intranet: An intranet is a private network based on the internet protocol such
as Transmission Control protocol and internet protocol. An intranet belongs to an
organization which is only accessible by the organization's employee or members. The main
aim of the intranet is to share the information and resources among the organization employees.
An intranet provides the facility to work in groups and for teleconferences.
Intranet advantages:
o Communication: It provides a cheap and easy communication. An employee of the
organization can communicate with another employee through email, chat.
o Time-saving: Information on the intranet is shared in real time, so it is time-saving.
o Collaboration: Collaboration is one of the most important advantage of the intranet. The
information is distributed among the employees of the organization and can only be
accessed by the authorized user.
o Platform independency: It is a neutral architecture as the computer can be connected to
another device with different architecture.
o Cost effective: People can see the data and documents by using the browser and
distributes the duplicate copies over the intranet. This leads to a reduction in the cost.
WIFI - Wireless Fidelity

Wifi is also known as Wireless Fidelity.

We are all familiar with Wi-Fi, which is available on our mobile phones, laptops, or wherever
Wi-Fi is supported. Wi-Fi is a wireless networking technology that permits to connect
wirelessly to a network or to other computer or mobile device. A circular radio frequency range
is used to transmit data in Wi-Fi.
Wireless Fidelity (Wi-Fi) is a generic term for the wireless network in the communication
norm. Wifi operates like a local area network without the use of a wire or cables.
WLAN stands for Wireless Local Area Network. IEEE 802.11 is the rule for
communication. WiFi uses the Physical Data Link Layer (PDLL) to operate.
Modern computing devices like laptops and mobile phones, as well as digital cameras and smart
TVs, all have Wi-Fi capabilities. The access point or base station to client connection or any
client-to-client connection within a certain limit.
The range relies on the router that offers radio frequency via Wi-Fi.
Currently, these frequencies function on 2.4 GHz and 5 GHz bandwidths.
Because the Wi-Fi adapter within the device is responsible for receiving the Wi-Fi signal, all
modern laptops and mobile devices are competent in using both bandwidths. All devices have
a default bandwidth of 2.4 GHz.

2.4 GHz bandwidth is capable of covering a large area, but the frequency is low, so the internet
speed is lower, and 5 GHz bandwidth can cover a smaller area, but the frequency is high, so the
internet speed is higher. Hence, Wifi is a wireless network protocol family based on IEEE
802.11 standards. Moreover, it allows nearby digital devices to exchange data via radio waves.
Worldwide, these are the one of the commonly used computer networks. They are used in house
networks to connect desktop or laptop or computers, tablets, smart TV, and printer to a wireless
router, as well as in public access points in coffee shop, hotel, library, and airport.In order to
qualify as Wi-Fi Certified, a product must pass interoperability certification evaluation. Wi-Fi is
a trademark of the Wi-Fi Alliance, a non-profit organisation. There were more than 800
companies represented in the Wi-Fi Alliance as of 2017.
Over 3,05 billion Wi-Fi-equipped devices were shipped worldwide each year as per the reports
of 2019. Ethernet (wired sibling)and Wi-Fi are developed to function seamlessly together.
Wi-Fi-enabled devices can be connected via wireless access points and wired devices, and the
internet.
Several IEEE 802.11 protocol norms specify the different Wi-Fi versions. The protocol standards
also specify how much bandwidth and speed can be achieved using various radio technologies.
Wi-Fi utilisesthe 2.4 gigahertz (120 mm) UHF and 5 gigahertz (60 mm) SHF radio bands,
which are segmented into various channels.
Only one transmitter at a time can communicate locally on a channel that is shared by multiple
networks. It is best to utiliseWiFi in a direct line of sight due to its relatively high absorption.
As a rule of thumb, an access point (or hotspot) has a range of about 20 metres (66 feet) for
the indoor environment, while some modern access points assert a range of up to 150 metres in
the outside environment.
Hotspot coverage can be as tiny as a small room with walls blocking radio waves or huge
comprising of an area of square kilometres (miles) utilising several inter-wining access points
with roaming allowed between each.
In recent years, Wi-Fi's speed and spectral efficiency have both risen.
Wi-Fi versions operating on appropriate hardware can now get speeds of over 1 Gbit/s at close
range as of 2019. (gigabit per second).
History of Wifi
o Wi-Fi is an old concept, but its execution is a new concept. ALOHA System is a wireless
network mechanism that was used to link Hawaii island through a network in 1971.
o ALOHA protocol was used for this, and packet transfer was used on the network in
order to accomplish this task. IEEE 802.11 protocol is added later.
o 1985 saw the release of a new network for broad use by the Federal Communications
Commission (FCC), which operates on frequencies between 900 Mhz and 5.8
GHz. Acknowledged as the ISM band. It can transmit data at 4 Mb/s. IBM also presented
a Token Ring LAN network for linking numerous computers.
o When waveLAN, a wireless cashier system, was invented in 1988, it operated at speeds
of 1 to 2 megabits per second on the Token Ring Local Area Network. IEEE
802.11LAN/MAN standards were introduced in
o This was followed by Vic Hayes (known as the "Father of WiFi") establishing IEEE
802.11 Working Group for Wireless LANs in 1990.
o In 1994, Alex Hills initiated a wireless network research project that covered seven
buildings wirelessly.
o This wireless network was later renamed IEEE 802.11a by the Commonwealth Scientific
and Industrial Research Organization (CSIRO) in 1996.
o After all of this, in 1997, the first version of Wi-Fi, 802.11, was released, which supports
a maximum link speed of 2 Mb/s.
o When the link speed was increased to 11 Mb/s in 1999, it was called 11b.

o An additional month passed before IEEE 802.11a was officially approved, which
provided up to 54 Mb/s link speed over the 5 GHz band, but with less range than 2.4
GHz.
o In 2003, 11g, a faster version, was released. Over 2.4 GHz, the speed ranges from 54 to
108 Mb/s.
o In the years that followed, 11i and 802.11e were added.
o Security was improved in 11i, while Voice over Wireless LAN and multimedia streaming
were added to 802.11e.
 o This was followed by the development in 2009 of the 802.11n standard, which supports
both radiofrequency bands (2.4 and 5GHz).
o Dual-band routers use both of these are utilised concurrently and can reach speeds of up
to 600 Mbps. As of 2014, a fresh version was launched in the 5GHz band with a
prospective speed of 1733 Mb/s 802.11ac is the name given to this version. This has
been the latest release of Wi-Fi up to this point.
o CISRO wireless LAN (Local Area Network) was selected as Australia's contribution to
the exhibition in Australia -A History of the World in 100 Objects in the National
Museum of Australia in 2016.
Usage and Application of Wifi
Many applications exist for Wi-Fi, including in all segments where computers or digital media
are used. Wi-Fi can also be used for entertainment.
As an example, the following applications are described:
o We use Wi-Fi every day. With Wi-Fi, we can connect to the internet from any Wi-Fi-
capable device.Wi-Fi allows us to have wireless communication, including streaming or
casting audio or video to any device.
o Data transfer rates are also very fast when using Wi-Fi to share files, data, etc., among
two or more computer or mobile phone.
o Another important attribute is the capability to print any document using a Wi-Fi printer.
o Wi-Fi can also be used as a HOTSPOT, providing Wireless Internet access for a
specific area. While the main network connection is active, consumers of Wi-Fi-enabled
devices can access the primary network connection via Hotspot, which provides them
with temporary internet connectivity. To create a hotspot, Wi-Fi
o adapters spread radio signals by utilising the owner's network connection.
 o Also one can create a Point-to-Point network using Wi-Fi or WLAN technology. Two
sites that are hard to reach by wire, such as two corporate office buildings, can be
connected using this method.
o VoWi-Fi is also recognised as voice-over Wi-Fi, which is another useful tool. Few
years ago, telecom firmsput forward theVoLTE (Voice over LTE) (Voice over Long-
Term Evolution ). In recent years, VoWi-Fi has become increasingly popular, allowing
us to make calls and anyone using our home Wi-Fi network. The only requirement is that
our mobile phone must be connected to Wi-Fi. Instead of using the mobile SIM network,
voice is transferred over Wi-Fi, resulting in very high voice quality. VoWi-Fi is already
supported by a large number of mobile phones.
o Internet via Wi-Fi in offices: In offices, all computer systems are linked to the Internet
via Wi-Fi. In the case of Wi-Fi, there is no need for complicated wiring. Also, the
network's speed is excellent. It's possible to present an entire Wi-Fi project, such as a
spreadsheet or ppt, to all participants at once.
o A cable break in Wi-Fi does not result in a loss of network connectivity, as it would be in
the case of a cable.
o By deploying routers at specific locations, a city can also provide network connectivity
using W-Fi. Because of its flexibility, schools, colleges, and universities have already
implemented Wi-Fi networks.
o As a positioning system, Wi-Fi can be used to recognise a device's area by detecting
the placements of Wi-Fi hotspots.
Types or Kinds of Wifi
As mentioned earlier, Wi-Fi has numerous kinds or standards. Here, the names of the standards
are defined.
o Wi-Fi-1 (802.11b, launched in 1999) - This version has link speed from 2Mb/s to 11
Mb/s over 2.4 GHz frequency band
o Wi-Fi-2 (802.11a) launched in 1999. After a month of releasing the previous version,
802.11a, was released, and it provides upto 54 Mb/s link speed over the 5 GHz band
o Wi-Fi-3 (802.11g) was launched in 2003. In this version, the speed was risen up to 54 to
108 Mb/s over 2.4 GHz
o 802.11i launched in 2004. This is equivalentto802.11g, but only the security feature was
enhanced in this version
o 802.11e launched in 2004. This is also the same as 802.11g; only Voice over Wireless
LAN and multimedia streaming are included.
 o Wi-Fi-4 (802.11n) launched in 2009. This version holds up both 2.4 GHz and 5 GHz
radio frequencies, and it provides up to 72 to 600 Mb/s speed.
o Wi-Fi-5 (802.11ac) launched in 2014. It supports a speed of 1733 Mb/s in the 5 GHz
band.
In 2020, Huawei launched 802.11ax, the latest version that can support 3.5 Gb/s; recognised as
Wi-Fi 6.
Working or Functioning of Wifi
What is the Wi-Fi protocol?
First and foremost, Wi-Fi is a wireless communication system that transmits networks using
electromagnetic waves. The radiofrequency is utilised in Wi-Fi because we understand that
there are several types of electromagnetic waves based on their frequency, including X-rays,
Gamma-rays, radio waves, microwaves, etc.
o Base station network or Ethernet(802.3) connection: It is the primary host network
from which the router receives its network connection.
o Access Point or Router - Network bridge, also known as an access point or router,
connects wired and wireless networks. A wired Ethernet connection is accepted, and the
wired connection is converted to a wireless connection, which is then spread via radio
waves.
o Accessing Device - There are several ways to gain access to information. From our
mobile, computer, etc., we access Wi-Fi and surf the web using Wi-Fi.
Also, routers and our devices read data in binary form. In this case, routers transmit radio waves
to our devices, obtaining and reading the waves in binary form. All of us are familiar with the
binary representation of a wave, in which the topmost pick is 1 and the lower pick 0 in binary.

Terminology of WIFI
Another term for Wi-Fi is "wireless LAN."
o SSID (Service Set Identifier)-WiFi networks are identified and distinguished from one
another by their service set identification (SSID) numbers, which are 32 characters long.
All gadgets are trying to communicate to the same SSID (Service Set Identifier). SSID
stands for "Service Set Identifier" and is the title of the wireless network.
 o WPA-PSK (Wi-Fi Protected Access- Pre-Shared Key): It's a programme created by
the Wi-Fi Alliance Authority to safeguard wireless networks using Pre-Shared Key
authentication. WPA comes in three varieties: WPA, WPA2, and WPA3. An encryption
method for Wi-Fi signals to keep out unwanted users.
o Ad hoc networks are used by Wi-Fi in order to transmit data. A point-to-point network
without an interface, it's a wireless mesh network.
Advantages of WIFI
The advantages of Wi-Fi Tt include
o A versatile network connection and the absence of complicated wiring requirements for
installation.
o Everywhere in the Wi-Fi range can access it.
o Independent users are not required to obtain regulatory approval.
o In addition, Wi-Fi Extenders make it possible to expand the network.
o It's easy and quick to set up.
o Only the SSID and password need to be configured.
o As part of its security measures, Wi-Fi networks encrypt radio signals using WPA
encryption.
o It is also more affordable.
o Hotspots are another feature that it offers.
o Roaming is supported as well.

Wi-Fi Disadvantages
o Mobile phones, laptops, and other devices with batteries consume a lot of power when
using Wi-Fi.
o Even when encryption is in place, security issues can still arise.
 o Wi-Fi can be attacked and accessed in the same way that recognised devices become
unidentified to the router.
o In comparison to a direct cable connection, the speed is slower.
o People can be harmed by it because it emits radiation like cell phones.
o Thunderstorms, for example, can interfere with Wi-Fi signals.
o Because it lacks a firewall, unauthorised access to Wi-Fi is possible.
o Since a router is required to access the internet via Wi-Fi, we can't access the internet if
the power goes out.

Alternatives to Wifi
Alternatives to Wi-Fi include several other wireless technologies:
o As a short-range network, Bluetooth is a great option.
o Mobile networks, used by mobilephonesand WiMax, for serving the users with long-
range wireless internet connection
o For long-range wireless with a low data rate, there is LoRa
o Reusing existing cables is one option.
o Home wires, like as telephone and power lines, are used by G.hn
 o There are a number of wired computer networking technologies that are viable
alternatives to Wi-Fi, such as:
o IEEE 802.3ah twisted pair
Bluetooth Technology in Mobile Computing
Bluetooth technology is a high speed and low powered wireless technology designed to connect
phones or other portable equipment for communication or file transmissions. This is based on
mobile computing technology. Following is a list of some prominent features of Bluetooth
technology:
o Bluetooth is also known as IEEE 802.15 standard or specification that uses low power radio
communications to link phones, computers and other network devices over a short distance
without using any type of connecting wires.
o As Bluetooth is an open wireless technology standard so, it is used to send or receive data to
connected devices present across a certain distance using a band of 2.4 to 2.485 GHz.
o In Bluetooth technology, the wireless signals transmit data and files over a short distance,
typically up to 30 feet or 10 meters.
o Bluetooth technology was developed by a group of 5 companies known as Special Interest Group
formed in 1998. The companies are Ericsson, Intel, Nokia, IBM, and Toshiba.
o The range of Bluetooth technology for data exchange was up to 10 meters in older versions of
devices, but the latest version of Bluetooth technology i.e., Bluetooth 5.0, can exchange data in
the range of about 40-400 meters.
o The average speed of data transmission in Bluetooth technology was around 1 Mbps in the very
first version. The second version was 2.0+ EDR, which provided the data rate speed of 3Mbps.
The third was 3.0+HS, which provided the speed of 24 Mbps. The latest version of this
technology is 5.0.
History of Bluetooth
There is an amazing story behind the history of Bluetooth technology. The Bluetooth wireless
technology was named after a Danish King named Harald Blatand. His last name means
"Bluetooth" in English. The name "Bluetooth" was awarded to this technology because the
Danish King named Harald Blatand was united the Denmark and Norway, same as Bluetooth
wireless technology is used to unite two disparate devices for communication or data
transmission.
Ericsson Mobile Communications started the development of Bluetooth technology in 1994. The
main motive behind the development of this amazing technology was to find an alternative to the
use of cables for communication between mobile phones and other devices. In 1998, 4 big
companies of that time named Ericsson, IBM, Nokia and Toshiba formed the Bluetooth Special
Interest Group (SIG), which published the 1st version of Bluetooth technology in 1999. After
that, four versions have been released. The latest version of this technology is Bluetooth 5.0.
The Architecture of Bluetooth Technology
 o In Bluetooth technology, the network of Bluetooth consists of a Personal Area Network or a
o Bluetooth's architecture is also called a "Piconet" because it is made of multiple networks.
o It contains a minimum of 2 to a maximum of 8 Bluetooth peer devices.
o It usually contains a single master and up to 7 slaves.
o Piconet provides the technology which facilitates data transmission based on its nodes, i.e.,
Master node and Slave Nodes.
o The master node is responsible for sending the data while the slave nodes are used to receive the
data.
o In Bluetooth technology, data transmission occurs through Ultra-High frequency and short-
wavelength radio waves.
o The Piconet uses the concept of multiplexing and spread spectrum. It is a combination of code
division multiple access (CDMA) and frequency hopping spread spectrum (FHSS) technique.
How does Bluetooth work?
As we stated that there is one master and up to 7 slaves may exist for a Bluetooth connection.
The master is the device that initiates communication with other devices. The master device
handles the communications link and traffic between itself and the slave devices associated with
it. The slave devices have to respond to the master device and synchronize their transmit/receive
timing with the master device's specified time.
Computer Network Components
Computer network components are the major parts which are needed to install the software.
Some important network components are NIC, switch, cable, hub, router, and modem.
Depending on the type of network that we need to install, some network components can also be
removed. For example, the wireless network does not require a cable.
Following are the major components required to install a network:
NIC
o NIC stands for network interface card.
o NIC is a hardware component used to connect a computer with another computer onto a
network
o It can support a transfer rate of 10,100 to 1000 Mb/s.
o The MAC address or physical address is encoded on the network card chip which is
assigned by the IEEE to identify a network card uniquely. The MAC address is stored in
the PROM (Programmable read-only memory).
There are two types of NIC:
 1. Wired NIC
2. Wireless NIC
Wired NIC: The Wired NIC is present inside the motherboard. Cables and connectors are used
with wired NIC to transfer data.
Wireless NIC: The wireless NIC contains the antenna to obtain the connection over the wireless
network. For example, laptop computer contains the wireless NIC.

Hub
A Hub is a hardware device that divides the network connection among multiple devices. When
computer requests for some information from a network, it first sends the request to the Hub
through cable. Hub will broadcast this request to the entire network. All the devices will check
whether the request belongs to them or not. If not, the request will be dropped.
The process used by the Hub consumes more bandwidth and limits the amount of
communication. Nowadays, the use of hub is obsolete, and it is replaced by more advanced
computer network components such as Switches, Routers.

Switch
A switch is a hardware device that connects multiple devices on a computer network. A Switch
contains more advanced features than Hub. The Switch contains the updated table that decides
where the data is transmitted or not. Switch delivers the message to the correct destination based
on the physical address present in the incoming message. A Switch does not broadcast the
message to the entire network like the Hub. It determines the device to whom the message is to
be transmitted. Therefore, we can say that switch provides a direct connection between the
source and destination. It increases the speed of the network.

Router
o A router is a hardware device which is used to connect a LAN with an internet
connection. It is used to receive, analyze and forward the incoming packets to another
network.
o A router works in a Layer 3 (Network layer) of the OSI Reference model.
o A router forwards the packet based on the information available in the routing table.
o It determines the best path from the available paths for the transmission of the packet.
Advantages Of Router:
 o Security: The information which is transmitted to the network will traverse the entire
cable, but the only specified device which has been addressed can read the data.
o Reliability: If the server has stopped functioning, the network goes down, but no other
networks are affected that are served by the router.
o Performance: Router enhances the overall performance of the network. Suppose there
are 24 workstations in a network generates a same amount of traffic. This increases the
traffic load on the network. Router splits the single network into two networks of 12
workstations each, reduces the traffic load by half.
o Network range

Modem
o A modem is a hardware device that allows the computer to connect to the internet over
the existing telephone line.
o A modem is not integrated with the motherboard rather than it is installed on the PCI slot
found on the motherboard.
o It stands for Modulator/Demodulator. It converts the digital data into an analog signal
over the telephone lines.
Based on the differences in speed and transmission rate, a modem can be classified in the
following categories:
o Standard PC modem or Dial-up modem
o Cellular Modem
o Cable modem

Cables and Connectors

Cable is a transmission media used for transmitting a signal.
There are three types of cables used in transmission:
o Twisted pair cable
o Coaxial cable
o Fibre-optic cable
Internet
Internet is a global network that connects billions of computers across the world with each other
and to the World Wide Web. It uses standard internet protocol suite (TCP/IP) to connect billions
of computer users worldwide. It is set up by using cables such as optical fibers and other wireless
and networking technologies. At present, internet is the fastest mean of sending or exchanging
information and data between computers across the world.
It is believed that the internet was developed by "Defense Advanced Projects Agency" (DARPA)
department of the United States. And, it was first connected in 1969.
Why is the Internet Called a Network?
Internet is called a network as it creates a network by connecting computers and servers across
the world using routers, switches and telephone lines, and other communication devices and
channels. So, it can be considered a global network of physical cables such as copper telephone
wires, fiber optic cables, tv cables, etc. Furthermore, even wireless connections like 3G, 4G, or
Wi-Fi make use of these cables to access the Internet.
Internet is different from the World Wide Web as the World Wide Web is a network of
computers and servers created by connecting them through the internet. So, the internet is the
backbone of the web as it provides the technical infrastructure to establish the WWW and acts as
a medium to transmit information from one computer to another computer. It uses web browsers
to display the information on the client, which it fetches from web servers.
The internet is not owned by a single person or organization entirely. It is a concept based on
physical infrastructure that connects networks with other networks to create a global network of
billions of computers. As of 12 August 2016, there were more than 300 crores of internet users
across the world.
How is the Internet set up?
Physical copper or optical fiber data transmission cables, as well as other networking
technologies like LAN, WAN, and MAN, are used to set up the internet. Even the 2g, 3g, and 4g
services, as well as Wi-Fi, need this physical cable arrangement in order to access the Internet
connection. The Internet Corporation for Assigned Names and Numbers (ICANN), a US-based
organization, is in charge of overseeing the management of the Internet and its related protocols,
including IP addresses.
How does internet work?
Before understanding this let us understand some basics related to internet:
The internet works with the help of clients and servers. A device such as a laptop, which is
connected to the internet is called a client, not a server as it is not directly connected to the
internet. However, it is indirectly connected to the internet through an Internet Service Provider
(ISP) and is identified by an IP address, which is a string of numbers. Just like you have an
address for your home that uniquely identifies your home, an IP address acts as the shipping
address of your device. The IP address is provided by your ISP, and you can see what IP address
your ISP has given to your system.
A server is a large computer that stores websites. It also has an IP address. A place where a large
number of servers are stored is called a data center. The server accepts requests send by the client
through a browser over a network (internet) and responds accordingly.
To access the internet we need a domain name, which represents an IP address number, i.e., each
IP address has been assigned a domain name. For example, youtube.com, facebook.com,
paypal.com are used to represent the IP addresses. Domain names are created as it is difficult for
a person to remember a long string of numbers. However, internet does not understand the
domain name, it understands the IP address, so when you enter the domain name in the browser
search bar, the internet has to get the IP addresses of this domain name from a huge phone book,
which is known as DNS (Domain Name Server).
For example, if you have a person's name, you can find his phone number in a phone book by
searching his name. The internet uses the DNS server in the same way to find the IP address of
the domain name. DNS servers are managed by ISPs or similar organizations.
Now after understanding the basics, let us see how internet works?

When you turn on your computer and type a domain name in the browser search bar, your
browser sends a request to the DNS server to get the corresponding IP address. After getting the
IP address, the browser forwards the request to the respective server.
Once the server gets the request to provide information about a particular website, the data starts
flowing. The data is transferred through the optical fiber cables in digital format or in the form of
light pulses. As the servers are placed at distant places, the data may have to travel thousands of
miles through optical fiber cable to reach your computer.
The optical fiber is connected to a router, which converts the light signals into electrical signals.
These electrical signals are transmitted to your laptop using an Ethernet cable. Thus, you receive
the desired information through the internet, which is actually a cable that connects you with the
server.
Furthermore, if you are using wireless internet using wifi or mobile data, the signals from the
optical cable are first sent to a cell tower and from where it reaches to your cell phone in the
form of electromagnetic waves.
The internet is managed by ICANN (Internet Corporation for Assigned Names and Numbers)
located in the USA. It manages IP addresses assignment, domain name registration, etc.
The data transfer is very fast on the internet. The moment you press enter you get the information
from a server located thousands of miles away from you. The reason for this speed is that the
data is sent in the binary form (0, 1), and these zeros and ones are divided into small pieces
called packets, which can be sent at high speed.
Uses of the internet
Generally speaking, the Internet may be used to exchange information with people all over the
world, communicate across great distances, and locate information or answers fast on almost any
subject.
Here are some examples of specific uses for the Internet:
o Using social media and content sharing.
o Instant messaging, video conferencing, Internet Relay Chat (IRC), Internet telephony, and email
are all examples of electronic communication. These all are used through the Internet.
o Access to online degree programs, courses, and workshops for education and self-improvement.
o Searching for jobs: To advertise available positions, submit job applications, and hire candidates
identified on social networking sites like LinkedIn, both employers and applicants use the
Internet.
Other examples include:
o Online dating
o Online gaming
o Research
o Reading electronic newspapers and magazines
o Online shopping, or e-commerce.
o Online discussion groups and forums
Difference between the World Wide Web and the Internet
The World Wide Web (also known as the Web) and the Internet are fundamentally dissimilar
from one another because the Web is a collection of information that can be accessed using the
Internet, whereas the Internet is a global network of networks that offers access to almost all
types of information. In other words, the Web is a service that was added to the Internet's
foundation.
The Web is the part of the Internet that gets the greatest traffic. One unique aspect of this is
hypertext, a rapid cross-referencing method. The majority of websites feature text that highlights
keywords or phrases by being a different color than the rest of the text. When a user selects one
of these words or phrases, they will be sent to the chosen website or page. Buttons, graphics, and
even particular areas of images are also utilized as hyperlinks.
On the Internet, there are billions of pages of information. The most popular web browsers are
Google Chrome, Firefox, and Internet Explorer. A web browser is used to surf the internet or do
online browsing. A certain Web site's look may vary slightly depending on the browser being
used. A certain browser's later or more updated versions have the potential to render more
complicated features like music files, sound, animation, and virtual reality.
Security and the Internet
Due to the volume of private and public information collected online, customers are at risk for
security attacks and data breaches. Crackers and hackers have access to networks and systems,
and they are able to steal personal data, such as login passwords or information on bank and
credit card accounts. Among the steps that may be taken to protect online privacy are:
o You can install antivirus and antimalware on your system.
o Generating complex, unique passwords that are impossible to decipher by anyone.
o A virtual private network (VPN) can be used, or at least a private browsing mode like the
Incognito window in Google Chrome.
o Only using HTTPS
o Keep private your all-social media accounts.
o Deactivate the autofill feature.
o Turn off the GPS of the device.
o Instead of just closing the tab or window, log out of accounts.
o Update cookies so that if a cookie is set, an alert is sent anytime.
o Spam emails should be avoided, and never open or download files from sources you are not
aware of.
o Need to use caution when using hotspots or public Wi-Fi.
Furthermore, the "dark web" is an additional component of the Internet. Standard browsers do
not allow users to access the dark web, which is hidden. It instead makes use of the Tor and I2P
browsers, which let users maintain complete anonymity. While this anonymity can be a fantastic
way to safeguard a user's security and freedom of speech online or for the government to conceal
confidential information, the dark web also fosters an environment that makes cybercrime, the
transfer of illicit commodities, and terrorism easier.

Search Engines
A search engine is an online answering machine, which is used to search, understand, and
organize content's result in its database based on the search query (keywords) inserted by the
end-users (internet user). To display search results, all search engines first find the valuable
result from their database, sort them to make an ordered list based on the search algorithm, and
display in front of end-users. The process of organizing content in the form of a list is commonly
known as a Search Engine Results Page (SERP).
Google, Yahoo!, Bing, YouTube, and DuckDuckGo are some popular examples of search
engines.

Advantages of Search Engine

Searching content on the Internet becomes one of the most popular activities all over the world.
In the current era, the search engine is an essential part of everyone's life because the search
engine offers various popular ways to find valuable, relevant, and informative content on the
Internet.

A list of advantages of search engines is given below -

1. Time-Saving
Search engine helps us to save time by the following two ways -

o Eliminate the need to find information manually.

o Perform search operations at a very high speed.

2. Variety of information
The search engine offers various variety of resources to obtain relevant and valuable information
from the Internet. By using a search engine, we can get information in various fields such as
education, entertainment, games, etc. The information which we get from the search engine is in
the form of blogs, pdf, ppt, text, images, videos, and audios.

3. Precision
All search engines have the ability to provide more precise results.

4. Free Access
Mostly search engines such as Google, Bing, and Yahoo allow end-users to search their content
for free. In search engines, there is no restriction related to a number of searches, so all end users
(Students, Job seekers, IT employees, and others) spend a lot of time to search valuable content
to fulfill their requirements.

5. Advanced Search
Search engines allow us to use advanced search options to get relevant, valuable, and informative
results. Advanced search results make our searches more flexible as well as sophisticated. For
example, when you want to search for a specific site, type "site:" without quotes followed by the
site's web address.
Suppose we want to search for java tutorial on javaTpoint then type "java
site:www.javatpoint.com" to get the advanced result quickly.

To search about education institution sites (colleges and universities) for B.Tech in computer
science engineering, then use "computer science engineering site:.edu." to get the advanced
result.

6. Relevance
Search engines allow us to search for relevant content based on a particular keyword. For
example, a site "javatpoint" scores a higher search for the term "java tutorial" this is because a
search engine sorts its result pages by the relevance of the content; that's why we can see the
highest-scoring results at the top of SERP.

Disadvantages of Search Engine

There are the following disadvantages of Search Engines -

o Sometimes the search engine takes too much time to display relevant, valuable, and
informative content.
o Search engines, especially Google, frequently update their algorithm, and it is very
difficult to find the algorithm in which Google runs.
o It makes end-users effortless as they all time use search engines to solve their small
queries also.