Computer Networks and Internet Use
1. Introduction to Computer Networks
A computer network is a group of computers and devices connected together to share resources, data, and communication services.
Main Purposes of Networks
- files and information
- Sharing Sharing hardware (printers, scanners)
- Communication (email, messaging, video calls)
- Accessing the internet
- Centralized storage and security
2. Types of Computer Networks
a) LAN (Local Area Network)
A network covering a small area such as:
- Home
- School
- Office
Characteristics:
- Fast speed
- Privately owned
- Low cost
Example:
Computers connected in a school lab.
b) WAN (Wide Area Network)
A network covering large geographical areas.
Characteristics:
- Connects cities or countries
- Uses public communication systems
- More expensive
Example:
The Internet.
c) MAN (Metropolitan Area Network)
Covers a city or large campus.
Example:
A university network across several buildings.
d) PAN (Personal Area Network)
Small network around one person.
Example:
Bluetooth connection between phone and earbuds.
3. Network Devices
Router
Connects networks and directs internet traffic.
Switch
Connects devices within the same network.
Modem
Connects a network to the internet service provider (ISP).
Access Point
Provides wireless internet connection.
Network Interface Card (NIC)
Allows a computer to connect to a network.
4. Transmission Media
Wired Media
- Ethernet cables
- Fiber optic cables
Advantages:
- Faster
- More secure
Disadvantages:
- Limited mobility
Wireless Media
- Wi-Fi
- Bluetooth
- Satellite
Advantages:
- Mobility
- Easy installation
Disadvantages:
- Can be slower
- More security risks
5. Network Topologies
A topology is the arrangement of devices in a network.
Star Topology
All devices connect to a central device.
Advantages:
- Easy to manage
- Failure of one device does not affect others
Disadvantages:
- Central device failure affects entire network
Bus Topology
All devices share one communication line.
Advantages:
- Cheap
Disadvantages:
- Difficult troubleshooting
Ring Topology
Devices connect in a circular pattern.
Advantages:
- Organized data flow
Disadvantages:
- Failure of one device can disrupt network
6. The Internet
The Internet is a worldwide network of interconnected computers.
Services Provided by the Internet
- Web browsing
- Video conferencing
- Cloud storage
- Online gaming
- Social networking
7. Internet Terminology
Website
A collection of web pages.
Web Browser
Software used to access websites.
Examples:
- Google Chrome
- Mozilla Firefox
- Microsoft Edge
URL (Uniform Resource Locator)
The address of a webpage.
Example:
https://www.example.com
ISP (Internet Service Provider)
A company that provides internet access.
8. Uses of the Internet
Education
- Online classes
- Research
- E-books
Communication
- Messaging apps
- Video calls
Examples:
- Zoom
Business
- Online shopping
- Banking
- Advertising
Entertainment
- Streaming music and movies
- Online games
Examples:
- YouTube
- Netflix
9. Advantages of the Internet
- Fast communication
- Easy access to information
- Online learning opportunities
- Remote work capability
- Global connectivity
10. Disadvantages of the Internet
- Cybercrime
- Privacy issues
- Addiction and distraction
- Spread of false information
- Viruses and malware
11. Internet Safety and Security
Strong Passwords
Use:
- Uppercase and lowercase letters
- Numbers
- Symbols
Antivirus Software
Protects computers from malware.
Examples:
- Norton Antivirus
- Avast Antivirus
Safe Browsing Tips
- Avoid suspicious links
- Do not share personal information
- Use secure websites (https)
- Keep software updated
12. Cybersecurity Threats
Virus
A harmful program that damages files.
Phishing
Fake messages designed to steal information.
Hacking
Unauthorized access to systems.
Malware
Software intended to harm computers.
13. Cloud Computing
Cloud computing allows users to store and access data online instead of on a local computer.
Examples:
- Google Drive
- Dropbox
- Microsoft OneDrive
Advantages:
- Access files anywhere
- Backup storage
- Easy sharing
Summary
Computer networks allow devices to communicate and share resources efficiently. The internet is the largest network and is widely used for education, communication, business, and entertainment. Safe and responsible internet use is important to protect information and maintain security online.