Networks can be convenient but not all are. In one kind of network, each computer would have to be connected to all the others. This is called point-to-point. Wiring something like this is a real nightmare! This is how it would look like. In this picture, each number represents a computer.

The two networks you should be familar with are LAN and WAN.

LAN stands for local-area network.
It is a computer network that spans short distances and connects a small number of computers.
Example of a LAN: computers in different rooms using the same printer
In this example, you would get put on a waiting line to use the printer. If both my friend Joe and I wanted to print something, and he clicks the "print" button first and I click it second, I'm going to have to wait for his paper to print out first before mine can print. Lines can get pretty long if there are many computers connected to the same printer!

WAN stands for wide-area network.
It is a computer network that connects two or more local-area networks, usually across long distances.
Example of a WAN: The Internet!