COMPUTER NETWORKING
COMPLETE REVISION GUIDE
Easy-to-understand notes • Key points • Exam questions • Answers
Designed for students preparing for Computer Networking examinations
Computer Networking Complete Revision Guide
,CONTENTS
1. 1. Introduction to Computer Networking
2. 2. Types of Computer Networks
3. 3. Network Topologies
4. 4. Network Components and Devices
5. 5. Transmission Media
6. 6. OSI Reference Model
7. 7. TCP/IP Model
8. 8. Network Protocols
9. 9. IP Addressing
10. 10. Network Security
11. 11. Wireless Networking
12. 12. Network Troubleshooting
13. 13. Important Networking Terms
14. 14. Quick Revision Questions
15. 15. Multiple-Choice Questions
16. 16. Answers and Explanations
17. 17. Final Revision Checklist
1. Introduction to Computer Networking
A computer network is a group of computers, phones, servers, printers and other devices connected so
that they can communicate and share information or resources.
Why networks are used
Sharing files and information.
Sharing devices such as printers and storage.
Sharing an internet connection.
Communication through email, messaging and video calls.
Centralized management of users and resources.
Accessing services from servers and cloud systems.
Basic parts of a network
Sender: the device that sends data.
Receiver: the device that receives data.
Transmission medium: the path used to carry data.
Network devices: equipment such as switches and routers.
Protocols: rules that control communication.
Advantages of networking
Fast communication.
Resource sharing.
Centralized data management.
Easier collaboration.
Backup and shared storage can be organized centrally.
Computer Networking Complete Revision Guide
, Disadvantages of networking
Security risks can increase.
A network failure can affect many users.
Networks require maintenance.
Equipment and installation can be expensive.
Poorly managed networks may become slow.
2. Types of Computer Networks
PAN – Personal Area Network
A PAN connects devices around one person, usually over a short distance. Bluetooth connections
between a phone and wireless earbuds are an example.
LAN – Local Area Network
A LAN connects devices within a small area such as a home, classroom, office or computer laboratory.
MAN – Metropolitan Area Network
A MAN covers a larger area than a LAN, such as several buildings or locations within a town or city.
WAN – Wide Area Network
A WAN connects networks over large geographical areas. The Internet is the most widely known example
of a WAN.
WLAN – Wireless LAN
A WLAN is a local area network that uses wireless communication, normally Wi-Fi, instead of network
cables.
Internet, Intranet and Extranet
Internet: a global network of interconnected networks.
Intranet: a private network used within an organization.
Extranet: a private network that provides controlled access to selected external users.
3. Network Topologies
Network topology describes how network devices are arranged and connected.
Bus topology
All devices share one main communication cable.
Simple and inexpensive for small setups.
A failure in the main cable can affect the network.
Performance can decrease as traffic increases.
Star topology
Each device connects to a central switch or hub.
Easy to manage and troubleshoot.
Failure of one cable normally affects only one device.
Computer Networking Complete Revision Guide
COMPLETE REVISION GUIDE
Easy-to-understand notes • Key points • Exam questions • Answers
Designed for students preparing for Computer Networking examinations
Computer Networking Complete Revision Guide
,CONTENTS
1. 1. Introduction to Computer Networking
2. 2. Types of Computer Networks
3. 3. Network Topologies
4. 4. Network Components and Devices
5. 5. Transmission Media
6. 6. OSI Reference Model
7. 7. TCP/IP Model
8. 8. Network Protocols
9. 9. IP Addressing
10. 10. Network Security
11. 11. Wireless Networking
12. 12. Network Troubleshooting
13. 13. Important Networking Terms
14. 14. Quick Revision Questions
15. 15. Multiple-Choice Questions
16. 16. Answers and Explanations
17. 17. Final Revision Checklist
1. Introduction to Computer Networking
A computer network is a group of computers, phones, servers, printers and other devices connected so
that they can communicate and share information or resources.
Why networks are used
Sharing files and information.
Sharing devices such as printers and storage.
Sharing an internet connection.
Communication through email, messaging and video calls.
Centralized management of users and resources.
Accessing services from servers and cloud systems.
Basic parts of a network
Sender: the device that sends data.
Receiver: the device that receives data.
Transmission medium: the path used to carry data.
Network devices: equipment such as switches and routers.
Protocols: rules that control communication.
Advantages of networking
Fast communication.
Resource sharing.
Centralized data management.
Easier collaboration.
Backup and shared storage can be organized centrally.
Computer Networking Complete Revision Guide
, Disadvantages of networking
Security risks can increase.
A network failure can affect many users.
Networks require maintenance.
Equipment and installation can be expensive.
Poorly managed networks may become slow.
2. Types of Computer Networks
PAN – Personal Area Network
A PAN connects devices around one person, usually over a short distance. Bluetooth connections
between a phone and wireless earbuds are an example.
LAN – Local Area Network
A LAN connects devices within a small area such as a home, classroom, office or computer laboratory.
MAN – Metropolitan Area Network
A MAN covers a larger area than a LAN, such as several buildings or locations within a town or city.
WAN – Wide Area Network
A WAN connects networks over large geographical areas. The Internet is the most widely known example
of a WAN.
WLAN – Wireless LAN
A WLAN is a local area network that uses wireless communication, normally Wi-Fi, instead of network
cables.
Internet, Intranet and Extranet
Internet: a global network of interconnected networks.
Intranet: a private network used within an organization.
Extranet: a private network that provides controlled access to selected external users.
3. Network Topologies
Network topology describes how network devices are arranged and connected.
Bus topology
All devices share one main communication cable.
Simple and inexpensive for small setups.
A failure in the main cable can affect the network.
Performance can decrease as traffic increases.
Star topology
Each device connects to a central switch or hub.
Easy to manage and troubleshoot.
Failure of one cable normally affects only one device.
Computer Networking Complete Revision Guide
