Okay kiddo, imagine you have a big box that can do lots of cool things like help you play games, watch movies, and write stories. Now imagine that instead of just you using that box, lots of other people want to use it too. That's what a computer bureau is.
A computer bureau is basically a big company that has lots and lots of those boxes we talked about, all in one place. Other people or companies that don't have their own boxes can use these boxes from the computer bureau to do their own work.
So, let's say your dad has a small business and needs to do some important work on the computer, but he doesn't have his own box. He can go to the computer bureau and rent one of their boxes by the hour or day to do his work. Then, when he's done, he can give the box back to the computer bureau and they'll take care of it.
The computer bureau does all the hard work to keep the boxes running and up-to-date so that everyone who uses them can be sure they'll work properly. This can be really helpful for people who need to use a computer for important things, but can't afford to buy their own box or don't want to worry about maintenance.
So, that's a computer bureau – a big company that rents out lots of computers for people and businesses to use so they don't have to worry about all the technical stuff themselves.