What is a client?
In one sentence: Your device and the app on it, the side that asks a server for things. Servers check what clients tell them instead of simply believing it.
A little more
In computing, the client is the side that asks and the server is the side that answers. Your browser is a client, and so is a game app when it talks to the game maker's computers.
Because the client runs on the user's own device, its owner can change it. That's why programmers say 'never trust the client': a server should check what it's told, like whether a score is even possible.
It's a bit like… A customer in a shop. The shopkeeper listens, but still checks the money before handing over the sweets.
See it in action
- 13How does a game know you really won?Play a 10-second star-catch game, then try to fool the high-score server: change the message your tablet sends, fake every move, build a wobbly bot.6 min · interactive
- 14How can lots of people play the same game together?Share a pretend park with friends in other houses: every move is a message to a shared world on a server.7 min · interactive