COMPUTER NETWORKING

Connecting People, Devices & Information

Connecting Devices, Sharing Information

Presented by: ZOYA RASHID
Class: ICS (PHY) – PART 2ND
Subject: COMPUTER SCIENCE
Teacher: SIR ASAD

1 — What Is Computer Networking?

A computer network is a group of two or more computers or devices connected together so they can communicate and share resources and information.

A network allows devices to share:

Files and data
Internet connections
Printers and other hardware
Applications and services
Messages and information

2 — Why Do We Need Computer Networks?

Computer networks make communication and information sharing easier and faster.

Main purposes:

Communication — sharing messages and information
Resource sharing — sharing printers, files, and internet
Data sharing — transferring information between devices
Collaboration — allowing people to work together
Centralized management — managing data and devices efficiently

3 — Basic Components of a Network

A computer network usually contains several important components:

i. Devices / Nodes

Computers, phones, printers, servers, cameras, etc.

ii. Network Media

The method used to connect devices.

Examples:

Ethernet cables
Fiber-optic cables
Wi-Fi
Bluetooth

iii. Network Devices

Devices that help networks communicate.

Examples:

Router
Switch
Modem
Access Point

iv. Protocols

Rules that allow devices to communicate correctly.

Example:
TCP/IP

4 — Types of Computer Networks

Networks can be classified according to their size and coverage area.

Main Types:

PAN — Personal Area Network
LAN — Local Area Network
MAN — Metropolitan Area Network
WAN — Wide Area Network

Other specialized types include:

WLAN — Wireless Local Area Network
CAN — Campus Area Network

i. PAN (Personal Area Network)

What is PAN?

A Personal Area Network is a small network used around one person.

It usually connects personal devices over a short distance.

Examples:

Phone connected to wireless earbuds
Phone connected to a smartwatch
Laptop connected to a Bluetooth mouse
Phone sharing internet through a hotspot

Range:

Usually a few meters.

Common technologies:

Bluetooth, USB, Wi-Fi

ii. LAN (Local Area Network)

What is LAN?

A Local Area Network connects devices within a limited area such as:

Home
School
Computer laboratory
Office
Building

Examples:

A school computer lab may connect 20 computers to the same network.

Advantages:

Fast communication
Easy file sharing
Resource sharing
Usually inexpensive to maintain

iii. WLAN (Wireless LAN)

What is WLAN?

A Wireless Local Area Network is a LAN that uses wireless communication instead of physical network cables.

Example:

The Wi-Fi network in your home is usually a WLAN.

Devices may include:

📱 Smartphones
💻 Laptops
📺 Smart TVs
🖨️ Wireless printers

Main technology:

Wi-Fi

iv. MAN (Metropolitan Area Network)

What is MAN?

A Metropolitan Area Network covers a larger area than a LAN, usually across a city or large campus.

Example:

A network connecting several branches of an organization throughout a city.

Characteristics:

Larger than LAN
Smaller than WAN
Can connect multiple LANs
Often used by organizations and service providers

v. WAN (Wide Area Network)

What is WAN?

A Wide Area Network connects networks over very large geographical areas.

It can connect:

Cities
Countries
Continents

The Internet is the largest example of a WAN.

Other examples include networks used by:

Banks
International companies
Universities
Government organizations

Comparison of Network Types

Type	Full Form	Coverage	Example
PAN	Personal Area Network	Very small	Phone + smartwatch
LAN	Local Area Network	Building/area	School lab
MAN	Metropolitan Area Network	City	City-wide organization network
WAN	Wide Area Network	Countries/world	Internet
WLAN	Wireless LAN	Local area	Home Wi-Fi

5 — Network Topology

What is Network Topology?

Network topology describes how devices are arranged and connected in a network.

Common topologies:

Bus Topology
Star Topology
Ring Topology
Mesh Topology
Tree Topology
Hybrid Topology

i. Star Topology

In a Star Topology, all devices are connected to a central device such as a switch.

Example:

Computer → Switch ← Computer

Advantages:

Easy to manage
Easy to add devices
Failure of one cable usually affects only one device

Disadvantage:

If the central device fails, communication can be disrupted for connected devices.

ii. Bus Topology

In a Bus Topology, all devices share a single main communication cable called the backbone.

Advantages:

Simple design
Uses less cable
Can be inexpensive for small networks

Disadvantages:

A problem with the main cable can affect the network
Performance can decrease as more devices are added

iii. Ring Topology

In a Ring Topology, each device is connected to two other devices, forming a circular arrangement.

Advantages:

Organized data transmission
Each device has a connection to the next device

Disadvantages:

A failure can affect communication around the ring
Adding or removing devices can be more difficult

iv. Mesh Topology

In a Mesh Topology, devices have multiple connections to other devices.

Advantages:

High reliability
Multiple paths for data
A single connection failure may not stop communication

Disadvantages:

Expensive
Requires more cables and connections
More difficult to manage

Example:

Some critical communication networks use mesh-like designs for reliability.

6 — Network Devices

Router

Connects different networks and directs data between them.

Switch

Connects devices within a network and forwards data to the appropriate device.

Modem

Connects a network to an internet service through the service provider’s connection.

Access Point

Provides wireless network access to devices.

Network Interface Card (NIC)

Allows a device to connect to a network.

7 — How Does a Network Work?

When you send information through a network:

i. Data is created

You send a message, open a website, or upload a file.

ii. Data is divided into packets

Large information is broken into smaller pieces.

iii. Packets travel through the network

Network devices direct the packets toward their destination.

iv. The destination receives the packets

The packets are reassembled into the original information.

v. The information is displayed

The receiver sees the message, website, image, or file.

8 — Network Protocols

A network protocol is a set of rules that allows devices to communicate.

Important protocols:

TCP/IP
The fundamental protocol suite used for communication over the Internet.

HTTP / HTTPS
Used for communication between web browsers and web servers.

FTP
Used for transferring files.

DNS
Converts domain names such as websites into IP addresses.

DHCP
Automatically provides network configuration information such as IP addresses.

9 — IP Address

An IP address is a numerical address used to identify a device on a network.

Example:

192.168.1.10

Devices use IP addresses to identify where data should be sent.

Two common versions:

IPv4
IPv6

IPv6 was developed to provide a much larger number of available addresses.

10 — Internet vs World Wide Web

These two terms are often confused.

Internet

The Internet is the worldwide network of interconnected networks.

World Wide Web (WWW)

The Web is a service that operates over the Internet and allows us to access websites and web pages.

In simple words:

Internet = Network infrastructure

Web = Websites and web pages accessed through it

11 — Uses of Computer Networking

Computer networks are used in almost every field.

Education

Online classes
Digital libraries
School computer labs

Business

File sharing
Email
Online meetings
Company systems

Healthcare

Sharing medical information
Hospital systems
Telemedicine

Banking

ATMs
Online banking
Electronic transactions

Entertainment

Online gaming
Streaming
Social media

12 — Computer Networks in Daily Life

We use networks every day, often without realizing it.

At Home

📱 Phone connected to Wi-Fi
💻 Laptop using the Internet
📺 Smart TV streaming videos
🖨️ Wireless printer

At School

💻 Computer lab
📡 Wi-Fi
🖨️ Shared printers
📁 Shared files

Outside Home

🏧 ATMs
📱 Mobile networks
🛒 Online shopping
🗺️ Navigation apps

13 — Advantages of Computer Networks

Major advantages:

> Fast communication
> Easy file sharing
> Resource sharing
> Internet access
> Collaboration
> Centralized management
> Cost reduction
> Access to information

Networks allow many people and devices to communicate efficiently.

14 — Disadvantages of Computer Networks

Despite their benefits, networks also have some disadvantages.

> Security risks
> Privacy concerns
> Viruses and malware can spread
> Network failures can interrupt services
> Installation and maintenance can cost money
> Requires technical knowledge

Proper security measures are important to reduce these risks.

15 — Network Security

What is Network Security?

Network security protects devices, data, and communication from unauthorized access and attacks.

Common security measures:

🔐 Strong passwords
🛡️ Firewalls
🔄 Software updates
🔒 Encryption
👤 User authentication
📡 Secure Wi-Fi settings
💾 Regular backups

16 — Real-Life Example: Home Network

A typical home network may contain:

Internet

↓

Router

↓

📱 Phone
💻 Laptop
📺 Smart TV
🎮 Gaming Console
🖨️ Printer

The router allows these devices to communicate with the local network and access the Internet.

17 — Real-Life Example: School Network

A school network may connect:

Computer laboratory
Teachers’ computers
Students’ devices
Printers
Servers
Wi-Fi access points

This allows the school to share resources and provide Internet access.

18 — Future of Computer Networking

Networking continues to develop with new technologies.

Future technologies include:

5G and future mobile networks
Internet of Things (IoT)
Cloud computing
Artificial Intelligence
Edge computing
Smart homes and cities
Faster fiber-optic networks

More devices are becoming connected every year.

CONCLUSION

Computer networking is an essential part of modern life.

It allows devices to:

Communicate → Share → Connect → Collaborate

From a smartphone connected to Bluetooth earbuds to the worldwide Internet, networks help people and devices exchange information quickly and efficiently.

Final Thought:

“A network connects devices, but communication connects people.”