What Are The Use Of Network?

Networking computers allows you to access files on a computer belonging to your network via the "shared" ability.  You can also access the internet from one computer to the other even if you computer isnt connected.  Just so long as a computer on your network it connected, you can access it.  You can also network computers together to play games with out having to use internet.
Hope this explains it.  There is a lot more that can be done with networking but those are the most common uses for every day people.