ICT (Information and Communication Technology)
For All Academic Departments Affiliated With University of Chitral.
• BS Computer Science (1st semester)
• BS Physics (1st semester)
• BS Political Science (1st semester)
Edited by: Zia Ur Rehman
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Computer software
Computer system
• There are two main components/elements of
a computer system.
Computer
Software Hardware
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Hardware
• Computer hardware are the physical parts or
components of a computer which can be
touched.
• Tangible components such as the monitor,
keyboard, mouse, CPU, Memory etc.
• Hardware is directed by the software to
execute any command or instruction. A
combination of hardware and software forms
a usable computing system.
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Software
• Software is a collection of instructions that
enable the user to interact with a computer,
its hardware, or perform specific tasks.
• without software, most computers would be
useless. For example, without your
Internet browser software, you could not surf
the Internet and without an operating system,
the browser could not run on your computer.
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• It can be a single program or may refer to a
number of programs collectively. These
instructions are defined in proper step by step
manner.
• A software acts as an interface between user
and hardware.
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Types of software
• The computer software is broadly divided into
two types.
• System software
• Application software
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System software
• System software are set of programs that
operate and control the computer system.
• System software is a type of
computer program that is designed to run a
computer’s hardware and application
programs.
• Examples are operating system (OS), device drivers
BIOS etc.
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System software
• System software does the following jobs.
– Support the development of other software.
– Support the execution of other software.
– Monitors the efficient use of various hardware
resources.
– Communicate with and controls the operations of
peripheral devices.
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Application software
• Application software is a type of software that
can be used for a variety of tasks.
• Application software is a program or group of
programs designed for end users according to
their needs such as creating documents,
spreadsheets, databases, doing online
research, sending email, creating graphics,
playing games etc.
• Examples are MS word, Excel, PowerPoint, Paint,
CorelDraw, browser, media players etc.
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Operating system
Components of computer system
• The computer system can be divided into four components
as follows.
1. Hardware: the physical components which can be touch
and see like memory, CPU, storage, input and output
devices etc.
2. Operating system: OS controls and coordinates the use of
hardware among various application programs for users.
3. Application programs: those softwares which are used by
users for variety of tasks like MS word, excel, paint,
browser etc.
4. Users: those people who uses the computer are called
users.
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A view of computer system
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Operating system
• An operating system is a program (system
software) that manages and operates
computer hardware.
• An operating system (OS) is the program that,
after being initially loaded into the computer,
manages all the other programs in a
computer.
• It acts as an interface between user and the
hardware.
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Operating system
• The application programs make use of the
operating system by making requests for
services through a defined application
program interface (API).
• Users can interact directly with the operating
system through a user interface such as a
command line or a graphical user interface
(GUI).
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Objectives/importance of OS
• Convenience:
– The primary objective of an OS is convenience for users. It
executes users programs and make it easy to solve users
problems. It also make computer system convenient to
use.
• Efficiency:
– Efficient operation of computer system is the responsibility
of OS. It is important for large, shared multi user system.
OS provides the facility to use the hardware in an efficient
manner.
• Ability to evolve (grow)
– OS provides development and introduction of new system
functions and development of new softwares.
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Functions of OS
• An operating system is the main controller of a
computer system, therefore it provides a
variety of functions to the computer and its
users.
– Process management
– Memory management
– File management
– I/O system management
– Secondary storage management
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1. Process management
• A program under execution is called process.
• Process management is that function of OS in
which it deals with running multiple processes
on a single processor.
• If there are more processes to run on a single
processor then the OS decides which process
should be assigned to the CPU for how much
time.
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2. Memory management
• Computer memory should be properly
managed.
• Memory is grouped into registers, cache
memory, RAM, secondary memory.
• Memory manager is responsible for the
coordination of these types of memories.
• Which memory is available, which memory is
to be allocated or de allocated and how to
move data among them.
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3. File management
• The data is stored in
computer memory in
files which are further
arranged in sub
directories and root
directory resulting in a
hierarchal file system.
• File manager keep track
of all these files and the
whole process is called
file management.
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4. I/O management
• Every computer has I/O system such as
monitor, keyboard, mouse, printer etc. all
these devices need proper management.
• I/O manager or device manager and the
process is called I/O system management.
• For using audio and video hardware device
drivers need to be installed.
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5. Secondary storage management
• Those devices which store data permanently
are called secondary storage devices like HDD,
CD, USB etc.
• OS manages secondary storage devices and
handle proper flow of data among primary
and secondary storage devices.
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Network
Elements of network
Types of network
Internet
WWW
Email
Network
• When we connect two or more computers for
sharing data and resources, is called a
network.
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Network
• A computer network is a series of points or nodes,
interconnected by communication paths for the
purpose of transmitting, receiving and exchanging
data.
• Network devices including switches and routers are
used to exchange information and to transport data
to endpoints.
• Every endpoint in a network has a unique identifier
called IP address that is used to indicate the source or
destination of the transmission. Endpoints can include
servers, personal computers, phones and many types
of network hardware.
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Elements of a network
• Basic elements of a computer network
include:
– Network devices
– Software
– Protocols
– Connection medium
– Client devices
• The interrelationship of these basic elements
constitutes the infrastructure of the network.
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Elements of Computer Network
• Network devices:
– The backbone of any network is the hardware that
runs it. Network hardware includes network cards,
routers, switches, modems, repeaters etc.
• Software:
– software that instructs network devices how to
connect to the network and how to interact with one
another.
• Protocols:
– Set of rules that governs data communication from
one device to another.
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Elements of a network
• Connection medium:
– The medium used to connect the network devices.
Wired networks will often use network cables
while wireless networks make direct connections
between devices using radio signals as the
medium.
• Client devices:
– Client devices are the computers and mobile
devices connected to the network.
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Types of network
• Local Area Network (LAN):
– The computers are geographically close together
(that is, in the same building).
• Metropolitan Area Network MAN):
– A data network designed for a town or city.
• Wide Area Networks (WAN):
– The computers are farther apart and are
connected by telephone lines or radio waves.
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LAN
• Local area network is a group of computers connected with each
other in a small places such as school, hospital, apartment etc.
• LAN is secure because there is no outside connection with the local
area network thus the data which is shared is safe on the local area
network and can’t be accessed outside.
• LAN due to their small size are considerably faster, their speed can
range anywhere from 100 to 100Mbps.
• LANs are not limited to wire connection, there is a new evolution to
the LANs that allows local area network to work on a wireless
connection.
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MAN
• MAN network covers larger area by connecting
LANs to a larger network of computers.
• In Metropolitan area network various Local area
networks are connected with each other through
telephone lines.
• The size of the Metropolitan area network is
larger than LANs and smaller than WANs(wide
area networks), a MANs covers the larger area of
a city or town.
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WAN
• Wide area network provides long distance
transmission of data. The size of the WAN is
larger than LAN and MAN.
• A WAN can cover country, continent or even a
whole world. Internet connection is an example
of WAN.
• Other examples of WAN are mobile broadband
connections such as 3G, 4G etc.
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Introduction to internet
• The Internet is a global system of
interconnected computer networks. It is
a network of networks that consists of millions
of private, public, academic, business, and
government networks.
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Internet
• The Internet is named for interconnection of
computer networks. It is a massive hardware
combination of millions of personal, business,
and governmental computers, all connected
like roads and highways.
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History of internet
• The Internet started in the 1960's under the
original name ARPAnet. ARPAnet was
originally an experiment in how the US
military could maintain communications in
case of a possible nuclear strike. With time,
ARPAnet became a civilian experiment,
connecting university mainframe computers
for academic purposes.
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History of internet
• As personal computers became more famous
in the 1980's and 1990's, the Internet grew
exponentially as more users plugged their
computers into the massive network. Today,
the Internet has grown into a public
spiderweb of millions of computers, all
connected by cables and by wireless signals.
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World wide web (www)
• The World Wide Web also known as the web,
WWW or W3 refers to all the public websites or
pages that users can access on their local
computers and other devices through
the internet. With a web browser, one can
view web pages that may contain text, images,
videos, and other multimedia.
• The Web is viewed by using free software called
web browsers.
• There are billions of web-pages on the web.
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What is URL?
• Web sites are found by their addresses on the
World Wide Web. These addresses are known as
URLs or Uniform Resource Locators. Every web
site has a URL assigned to it, so both searchers
and Web servers can find them quickly and easily.
• Example
• http://www.google.com
• http://www.facebook.com
• http://www.yahoo.com
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What are Applications of Internet?
• Communication
• Job Search
• Online Shopping
• Web Browsing
• Research
• E-Commerce
• Online Payments
• Social Networking
• Education
• Entertainment
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1. Communication
• Internet is used for
communication purposes.
• Some popular internet
Communication
applications are:
– Email
– Skype
– Google Meet
– Zoom
– WhatsApp
– Facebook Messenger
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2. JOB search
• In today's digital world it is
very easy to find the job of
your choice.
• Today you can easily find
jobs related to your skills
through the internet and
give a direct interview
online.
– Naukri.com
– Monster.com
– Freshersworld.com
– Indeed.com
– Glassdoor
– ZipRecruiter
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3. Online shopping
• Today the whole world is
doing online shopping
through the internet, sitting
at home and you can also
shop online from home
through the internet.
– Amazon
– FlipKart
– Paytm Mall
– ShopClues
– Myntra
– Snapdeal
– Meesho
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4. Web Browsing
• Searching the internet
with the help ofaweb
browser is called web
browsing or web
searching.
• Some famous web
browsers are:
– Internet Explorer.
– Google Chrome.
– Mozilla Firefox.
– Safari.
– Opera.
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5. Research
• Internet helps
researchers to make
their work easy. They
can search about topics
online about their
research.
• They can access
thousands of research
papers with the help of
internet.
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6. E-Commerce
• E-commerce means putting
your shop online and selling
any of your items online. By
doing this, your business
becomes local to global,
that is, you can sell your
goods to the people of
other cities as well.
– Amazon
– Flipkart
– Meesho
– Shopify
– Paytm Mall
– Dukaan
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7. Online Payment
• In today's digital age,
now everyone is paying
any bill online instead
of giving cash.
• You can pay any bill
through an online
payment.
– Easypaisa
– Jazzcash
– Paypall
– Google pay etc
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8. Social networking
• Social networking is also a
good platform, through which
you talk to people. Today
millions of people around the
world are using social
networking sites. Through
social networking sites, you
can make connections with
friends, family, classmates,
customers, and clients.
– Facebook
– Instagram
– Twitter
– LinkedIn
– YouTube
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9. Education/E-learning
• Today is the era of e-
learning in the present
time, e-learning means
electronic learning which
means you can now study
from anywhere through
e-learning.
– Byjus
– Topper
– Vedantu
– Unacademy
– Quick Learn Computer
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10. Entertainment
• Today there are many
such internet
applications that can
entertain you. You can
watch anything on
these entertainment
applications. Like -
Movies, Web series,
Cartoons, Serials,
Cricket, News, Comedy,
etc.
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Email
• Short for electronic mail.
• e-mail or email is information stored on a
computer that is exchanged between two
users over telecommunications.
• More simply e-mail is a message that may
contain text, files, images, or other
attachments sent through a network to a
person or group of persons
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Email address
• An email address is a unique identifier for an
email account. It is used to both send and
receive email messages over the Internet.
Similar to physical mail, an email message
requires an address for both the sender and
recipient in order to be sent successfully.
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Email address
• Every email address has two main parts: a
username and domain name. The username
comes first, followed by an at (@) symbol,
followed by the domain name. In the example
below, "mail" is the username and
"techterms.com" is the domain name.
alibaba@gmail.com
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Email providers
• Gmail
• Yahoo mail
• Hotmail
• Ymail
• Outlook etc.
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Computer security threats
• Computer Security Threats are possible
dangers that can affect the smooth
functioning of your PC.
• These may be a small piece of adware or a
harmful Trojan malware.
• In the present age, computer security threats
are constantly increasing as the world is going
digital.
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Types of Threats
• There are two types of computer threats
– Physical threats
• Internal
• External
• human
– Non physical threats
• Malware
• Virus
• Spyware
• Worms
• Trojan
• DoS attacks
• Phishing
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Physical Threats
• A physical danger to computer systems can be an
event that could result in data loss or physical
damage. It can be classified as:
– Internal: Short circuit, fire, non-stable supply of
power, hardware failure due to excess humidity, etc.
cause it.
– External: Disasters such as floods, earthquakes,
landscapes, etc. cause it.
– Human: Destroying of infrastructure, hardware, thefts
and unintentional/intentional errors are among the
threats.
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Non-physical threats
• A non-physical threat is a possible source of an
incident that could result in:
– Slow down the business operations that depend on
computer systems.
– Sensitive – data or information loss
– Keeping track of other’s computer system activities
illegally.
– Hacking id & passwords of the users, etc.
• The non-physical threads can be commonly
caused by:
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Non-physical threats
• Malware:
– Malware, short for “malicious software,” refers
to any disturbing software to steal data and
damage or destroy computers and computer
systems. You may notice that your system is
processing at a slower rate than usual.
– Examples of common malware include viruses,
worms, Trojan viruses, spyware, adware, and
ransomware.
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• Virus:
– It is a program that replicates itself and infects
your computer’s files and programs and make
them inoperable.
– It is a type of malware that spreads by inserting a
copy of itself and become a part of another
program.
– It spreads with the help of software or
documents.
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• Worms:
– Computer worms are similar to viruses in that
they replicate themselves and can impose
similar damage.
– Worms do not require a host program or human
assistance to spread.
– Worms don’t change programs they replicate
themselves over and over.
– They just eat resources to make the system down.
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• Spyware:
– Spyware is a type of computer program that
tracks, records, and reports a user’s activity
(offline and online) without their permission for
the purpose of profit or data theft.
– Sources: websites, email, chat
– Example: adware
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• Trojan:
– A Trojan horse is malicious software that is
hidden (masked) as a useful host program.
When the host program is run, the Trojan
performs a harmful/unwanted action
– It appears to be legal yet has the ability to take
control of your computer.
– It is designed to disrupt, steal or harm your data
or network.
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• Denial Of Service Attacks:
– A Denial of Service attack is one in which an
attacker tries to prohibit (stop) legal users from
obtaining information or services.
– An attacker tries to make a system or network
resource unavailable to its users.
– The web servers of large organizations such as
banking, commerce, trading organizations, etc. are
the victims.
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• Phishing:
– Phishing is a type of attack that is frequently used
to obtain sensitive information from users, such as
login credentials and credit card details by sending
spam, malicious Web sites, email messages, and
instant chats.
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How to make your system secure?
• Always keep a backup of your data.
• Install firewall software and keep it updated every
time.
• Make use of strong and difficult to crack passwords
• Install antivirus and keep it updated every time.
• Timely scan your complete system.
• Before installing any program, check whether it is safe
to install it.
• Take extra caution when reading emails that contain
attachments.
• Always keep your system updated.
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Database
• A database is a shared collection of
logically related data designed to meet
the requirements of different users of an
organization.
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Database Approach
Library Examination Registration
Library Examination Registration
Applications Applications Applications
Database Management System
University
Students
Database
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Characteristics of Relational Database
• Information is stored in the form of tables.
• A table contains rows and columns.
• Primary keys are used for unique identification
of rows.
• Foreign keys are used to link tables.
• SQL is used for data access.
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Number system
• A number system is a term used for a set of
different symbols or digits which represents a
numerical value.
• Following are four commonly used number
systems.
– Decimal number system
– Binary number system
– Octal number system
– Hexadecimal number system
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Decimal number system
• The most popular and commonly used
number system is the decimal number system.
Also called natural number system because it
is used by humans.
• It is composed of ten symbols or digits and
hence it is called decimal system.
• It is also called base-10 number system.
• 0 12 3 4 5 6 7 8 9
• 0 is the smallest and 9 is the largest value.
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Decimal number system
• (345)10 means 3x102 +4x101 + 5x100
• 300+40+5=345
• 3 is the most significant digit
• 5 is the least significant digit.
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Binary number system
• Binary number system comprising of two digits as binary
means two.
• In binary number system there are only two values 0 and 1.
• The base of binary number system is 2, base-2
• It is a natural number system for hardware.
• 0 represents the off and 1 represents the on state of the
circuit.
• The leftmost binary digit is the most significant bit (MSB)
while the rightmost digit is the least significant bit (LSB).
• 10001101
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Octal number system.
• Octal means eight
• So octal number system consists of 8 digits 0-7
• 01234567
• The base of this system is 8, base-8
• Each digit or symbol determines its value in
the power of 8.
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Hexadecimal number system
• Hexa means 16.
• Hexadecimal number system consist of 16
digits.
• 0123456789ABCDEF
• Consist of numbers from 0-9 and alphabets
from A-F.
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comparison
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• Inter-conversion of number system is not
included in these notes
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