If you want to know the manufacturing process of most computers these days because you might want to build your own one day, here is a brief overview of how it is done. There are, of course, multiple ways that a computer is created, but here is what goes inside your computer before it starts looking like a sleek little box.
First, the computer manufacturing company collects all the pieces it needs to make the computer. They contact the PCB manufacturer to make the circuit boards that go into it. They contact a chip company like Intel to install their processors onto the boards and then they consult various other companies about DVD drives, graphics cards etc. Once these are all gathered in one place, they put it together in a large factory. They shove all these into a small plastic or aluminum case, and they sell it to you for a rather large mark up.
Your personal computer can do some amazing things and it is made up of many parts from many other companies. If you want to do some more research, you can find out exactly where those parts came from and who made them. If your trying to build your own computer complete with flexible PCBs, processors, and all the rest, then it might be a great idea.