The internet is a network of networks. Many separate networks agree to connect. They send data with the Internet Protocol.

Computers on the internet follow shared sets of rules called protocols. One set of rules is TCP. It makes sure packets arrive complete and in order.

A computer cuts a long message into many packets. Each one gets a label that says where it is going. Packets can arrive out of order. The receiving computer puts them back in the right order. If one gets lost or damaged, the receiving computer can ask for just that packet again.

A packet moves from machine to machine. Each machine looks at the destination address. Then it passes the packet along. A router decides where to send packets next.

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. If the server cannot find the page, it answers with a 404 message.

Tim Berners-Lee invented the World Wide Web in 1989. He was working at CERN. On 30 April 1993, CERN made the web software free for anyone to use.

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, besides the web.

As of November 2026, almost all the data between countries goes through cables laid on the sea floor. As of November 2026, most damage to these cables comes from fishing and ships dragging anchors. It does not come from sharks. If one breaks, the network keeps running over the others while it is repaired.

Words to know

• protocols: shared rules
• router: sends packets onward
• packets: small pieces