Introduction

What is a computer network?

A computer network is a system that connects different computing devices (like computers, phones, servers) to share resources and communicate with each other.

Think of a computer network like a postal system, but for digital information. Just as the postal service helps people send letters and packages to each other, computer networks help devices share information, whether it’s sending an email, watching a video, or browsing websites.

The Internet, which you probably use every day, is actually the world’s largest computer network. It’s so big that we often call it a “network of networks” - imagine it as thousands of smaller postal systems all working together to deliver information anywhere in the world.

For this to work, we need a few key things. First, we need the actual devices - these could be your laptop, smartphone, or the servers that store websites. Then we need ways to connect these devices, which might be physical cables (like the ethernet cable you might plug into your computer) or wireless connections (like WiFi). Finally, we need special devices called routers and switches that act like post offices - they help direct information to the right destination.

But here’s the interesting part: for all these different devices to understand each other, they need to speak the same language. In computer networking, we call these languages “protocols.” It’s similar to how people need to speak the same language to understand each other. Different protocols handle different jobs - some handle web browsing, others handle email, and so on.