The internet is a very large group of computers. They are joined together so they can talk to each other. Cables can join them. So can wireless signals, such as Wi-Fi.

A server is a computer. It stores websites. It gives them to other computers that ask.

Every device on the internet has its own address. The address is made of numbers. It is called an IP address. An IP address is like a street address. It says where a device can be found.

The Domain Name System works like an address book for websites. When you type a website name, DNS finds the IP address of the server where it lives. Domain names are easier for people to remember than long strings of numbers.

To open a website, a browser first uses DNS to find the server's address. Then it asks that server for the page. HTTP is the language that browsers and servers use to talk to each other. A web server finds the page your browser asked for. It sends it back. If it cannot, it answers with a 404 message.

Computers send messages across the internet in small pieces called packets. Each packet is like an envelope. It holds a piece of the message. It also holds a label with the sender, the receiver and its number.

Packets can arrive out of order. The receiving computer puts them back in the right order. A packet may get lost or damaged. Then it can ask for just that packet again, not the whole file.

The ARPANET was the internet's direct forerunner. It began with four computers in late 1969.

Tim Berners-Lee invented the World Wide Web in 1989. He worked at CERN. The web and the internet are not the same. The internet is the network. The web is one service that runs on it. Email is another service built on top of the internet.

As of November 2026, almost all the data between countries goes through cables laid on the sea floor.

Words to know

• server: gives out pages
• packets: small pieces
• forerunner: earlier version
• wireless: without cables

The short version

The internet is a very large group of computers joined together by cables or wireless signals so they can talk to each other. When you open a website, your device asks a computer called a server, and the server sends the page back. Computers send messages across the internet in small pieces called packets.

Quick facts

• Every device on the internet has its own address made of numbers, called an IP address.
• The Domain Name System works like an address book for websites.
• Tim Berners-Lee invented the World Wide Web in 1989 while working at CERN, a physics laboratory.
• On 30 April 1993, CERN made the web software free for anyone to use.
• As of November 2026, almost all the data that travels between countries goes through cables laid on the sea floor.