Introduction to Computer Networks

What is a Computer Network?

A computer network is a group of two or more computers or devices linked together to share data, resources (such as printers) and communicate with one another. Networks allow information to move quickly between devices, whether in the same room or across the world.

Types of Networks

• LAN (Local Area Network): connects computers within a small area such as a school, home, or single office building.
• WAN (Wide Area Network): connects computers over a large geographical area, such as between cities or countries. The Internet is the largest WAN in existence.
• MAN (Metropolitan Area Network): covers a larger area than a LAN but smaller than a WAN, such as a whole city.

Network Devices

Several devices help build and manage a network:

• Router: directs data between different networks and connects a local network to the internet.
• Switch: connects multiple devices within the same network and directs data to the correct device.
• Modem: converts digital signals from a computer into signals that can travel over telephone or cable lines, and back again.
• Network cable / Wi-Fi: the physical or wireless medium through which data travels.

Network Topologies

A topology is the arrangement of devices in a network. Common topologies include the bus topology (all devices connected to a single central cable), star topology (all devices connected to a central device such as a switch), and ring topology (devices connected in a closed loop).

Benefits of Networking

Networking allows resource sharing (like one printer for many computers), faster communication through email and messaging, easier file sharing, and centralised data management. It is the foundation of the modern Internet, which connects billions of devices worldwide.