A network is basically a group of computers agreeing to talk to each other on some sort of wire or electromagnetic wave or fiber optic cable. The telephone companies or other large providers sell connectivity to Regional ISPs who lease part of their own connectivity to local ISPs or end users. The local ISPs then also sell part of their connectivity to other end users. Information is passed along these networks like a bucket in an old-fashioned fire brigade. The center of the Internet universe are the servers .
Servers are computers that store lots of information for other computers to download and view.
When a computer calls up a server and asks for a web page or file to download it's called a client . Since you are looking at our web page, you are a client and our computer is the server, sending our web page to you over a tangle of wires and routers and other stuff too technical to mention. The reason this is possible is that computers talk to each other through a series of languages called protocols . The next time you see an ad for a major company on the TV or in a magazine, keep your eye out for the website address. You see, every computer that is attached to the Internet has an address that helps other computers locate it.