What Is the Internet?

Introduction

You use it all day, but what is the internet? It is not a cloud, and it is not the same thing as a website. Understanding the basics makes everything else about technology easier.

The simple explanation

The internet is a huge network of connected computer networks that agree on common rules for sending data.

Your home Wi-Fi is one small network. Your internet provider connects it to bigger networks, which connect to others around the world, using cables (many under the sea), fibre, and wireless links.

The internet is not the web

• The internet is the network and the rules for moving data.
• The web (World Wide Web) is one service that runs on it: web pages you open in a browser.
• Email, video calls, games and app updates also use the internet without being the web.

Data travels in packets

Big files are not sent in one piece. They are cut into many small packets. Each packet carries part of the data plus the address it is going to. Packets may take different routes, and the receiving device puts them back in order. If one is lost, it can be sent again.

Sending small packets on shared routes makes the network efficient and resilient: if one path fails, others can be used.

The rules: protocols

Devices follow shared rules called protocols. You will meet these in this course:

• IP for addressing and routing packets
• DNS for turning names into addresses
• HTTP and HTTPS for web requests

Clients and servers

When you open a site, your device is the client. It asks for something. A server is a computer that answers. Servers are just computers that are always on, connected, and set up to respond.

Try it yourself

Think of one thing you did online today that was not the web, such as a video call or app update. Describe who the client was and what the server did.

Summary

• The internet is a global network of networks that follow shared rules.
• The web is one service that runs on the internet.
• Data travels as small packets, and clients ask servers for things.