If you own more than one computer, chances are you already have a network. These days, most broadband service providers throw in a router with a new connection. Typically it has four slots on the back, which means that you can connect up to four computers to the Internet simultaneously without adding any other hardware. Once you connect a second computer to the router, you have a little network of your own. The next logical step for most people is to plug in a network-enabled printer into the router so that they can print to it from any of the computers on the network.