Computer Network

A computer network is a collection of two or more computers and other devices (such as printers, servers, and smartphones) that are connected to each other to share data, resources, and services.

Objectives of Networking

  • Share files and information.
  • Share hardware resources (printers, scanners, storage).
  • Share software and applications.
  • Enable communication through email, messaging, and video conferencing.
  • Access the Internet.

 

Components of a Computer Network

  • Computers/Devices – Clients, servers, laptops, smartphones.
  • Network Interface Card (NIC) – Connects a device to the network.
  • Transmission Media – Ethernet cables, fiber optic cables, or wireless signals.
  • Networking Devices – Hub, Switch, Router, Modem, Access Point.
  • Network Software – Operating systems and communication protocols.

 

Classification of Networking

Computer networks are classified according to the geographical area they cover.

1. LAN (Local Area Network)

A Local Area Network (LAN) connects computers and devices within a small geographical area, such as a room, office, school, laboratory, or building.

Characteristics

  • Covers a small area.
  • High data transfer speed.
  • Usually owned and managed by a single organization.
  • Uses Ethernet cables or Wi-Fi.

Advantages

  • Fast communication.
  • Easy resource sharing.
  • Low operating cost.
  • High security because it is privately managed.

Disadvantages

  • Limited coverage area.
  • Requires network administration.
  • Failure of central equipment can affect the network.

Applications

  • Schools and colleges.
  • Offices.
  • Computer laboratories.
  • Libraries.

 

2. MAN (Metropolitan Area Network)

A Metropolitan Area Network (MAN) connects multiple LANs across a city or large campus.

Characteristics

  • Covers several kilometers.
  • Faster than WAN but slower than LAN.
  • Often managed by government organizations or Internet Service Providers (ISPs).

Advantages

  • Connects multiple offices across a city.
  • Supports high-speed communication.
  • Shares resources over a wider area.

Disadvantages

  • Higher installation cost.
  • More complex management.
  • Requires specialized networking equipment.

 

3. WAN (Wide Area Network)

A Wide Area Network (WAN) connects computers and networks over large geographical areas, such as countries or continents. The Internet is the largest example of a WAN.

Characteristics

  • Covers very large distances.
  • Uses leased lines, fiber optics, satellites, or mobile networks.
  • Connects many LANs and MANs.

Advantages

  • Global communication.
  • Supports remote work and online collaboration.
  • Enables centralized data access.
  • Connects branches across different locations.

Disadvantages

  • Expensive to establish and maintain.
  • Slower than LAN due to long distances.
  • More security challenges.

 

4. PAN (Personal Area Network)

A Personal Area Network (PAN) is a network that connects devices within a person’s immediate surroundings, usually within about 10 meters.

Characteristics

  • Very small coverage area.
  • Uses Bluetooth, USB, or Wi-Fi Direct.
  • Designed for personal devices.

Advantages

  • Easy to set up.
  • Low cost.
  • Portable and convenient.
  • Low power consumption.

Disadvantages

  • Very limited range.
  • Supports only a few devices.
  • Lower speed than LAN for large data transfers.
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