How does the internet work?

You tap a screen and a video plays, or a message pops up from a friend far away. Where does it all come from, so fast? Welcome to the internet.

A giant web of computers

The internet is millions and millions of computers all joined together, all over the world. They are linked by long cables — some even run along the bottom of the sea! — and by invisible radio signals through the air. Joined up like this, they can all share things with one another.

Messages travel in tiny pieces

When you watch a video, it doesn’t arrive all in one lump. It is chopped into lots of tiny pieces. Each piece zooms across the cables to your device, where they all snap back together in the right order — so quickly that the video plays smoothly. A message to a friend travels in exactly the same way.

Computers that wait to help

The pictures, games and videos you ask for are kept on special always-on computers called servers. When you tap a link, your device sends a little request to a server, and the server sends the page or video back to you. It is like asking a giant library for a book and getting it in the blink of an eye.

Wonder fact: Your messages can cross the whole planet through undersea cables in less than a second — quicker than you can say “hello”!