There are bigger computers that many people at a time can use. These are called "Mainframes," and these computers do all the things that make things like the internet work. You can think of a personal computer like this: the personal computer is like your skin: you can see it, other people can see it, and through your skin you feel wind, water, air, and the rest of the world. A mainframe is more like your internal organs: you never see them, and you barely even think about them, but if they suddenly went missing, you would have some very big problems.