Unit 6.3

Networking Basics: Network Types and Topologies

IT 231: IT and Application

Learning Objectives

By the end of this chapter, you will be able to:

✅ Define what a computer network is.
✅ Differentiate between a Local Area Network (LAN) and a Wide Area Network (WAN).
✅ Describe the common network topologies: Bus, Star, and Ring.

What is a Computer Network?

A computer network is a collection of two or more computers and other hardware devices connected together to share resources and exchange data.

Think of it as a digital team, where each member can communicate and share tools.

Components: Computers, printers, routers, switches.
Purpose: Share files, printers, internet access, and more.

Network Types 📊

Networks are most often classified by their geographical scope.

Local Area Network (LAN)

Covers a small, limited area like a single building or campus.

Wide Area Network (WAN)

Covers a broad geographical area, like a city, country, or the entire globe.

Deep Dive: Local Area Network (LAN)

A network that connects computers within a limited geographical area, such as a single building or a school campus.

Scope: Small (office, home, lab)
Purpose: Share resources like printers and files.
Speed: Typically very fast.

Example: The computer network in your university library, connecting all the PCs, printers, and servers together.

Deep Dive: Wide Area Network (WAN)

A network that covers a broad geographical area, often by connecting multiple LANs together.

Scope: Large (city, country, global)
Structure: A network of networks.
Speed: Slower than a LAN due to distance.

The most famous example of a WAN is the Internet itself!

What is Network Topology? 🔍

Network Topology refers to the physical layout or arrangement of the devices on a network. It's the network's blueprint.

We'll explore the three most common historical and modern topologies:

Bus

Ring

Star

Bus Topology

All devices are connected to a single central cable, called the bus or backbone.

How it works:

Data is sent down the entire cable.
All devices see the data, but only the intended recipient accepts it.
Simple and inexpensive to set up.

Major Disadvantage ⚡
If the main cable fails, the entire network goes down.

Ring Topology

All devices are connected in a closed loop or ring. Data travels around the ring, typically in one direction.

How it works:

Each device receives data and passes it along to the next one.
Prevents data collisions since data flows in one direction.

Major Disadvantage ⚡
A failure in one device or cable can break the loop and take down the entire network.

Star Topology ⭐

All devices are connected to a central device, like a hub or a switch. This is the most common topology in modern LANs.

How it works:

All data passes through the central hub/switch.
Easy to add or remove devices.
Easy to troubleshoot.

Key Advantage ✅
If one cable fails, only that single device is affected. The rest of the network remains functional.

Networking in Nepal: Real-World Examples

LAN Example

A branch of a commercial bank like NIC Asia in Pokhara. All the teller computers, manager's PC, and printers are connected in a LAN, likely using a Star topology with a central switch.

WAN Example

The network of an Internet Service Provider like WorldLink. They connect their LANs in various cities (Kathmandu, Biratnagar, Nepalgunj) across the country using a wide-area fiber optic network. This forms a national WAN.

Summary & Key Takeaways 🎯

A network is a group of connected computers that share resources.
Networks are classified by size: LANs are local (office), and WANs are wide-area (Internet).
Topology is the physical layout of a network (its "map").
While Bus and Ring were used historically, the Star topology is the reliable, modern standard for LANs.

Thank You!

Any questions?

Next Up: Unit 7.1 - The History and Management of the Internet

Course Home | Back to Unit 6