purpose of a network?

3 main reasons: 

1.) To share one internet connection among multiple

computers via NAT

 
2.) To share files 

3.) Security

what is a network?

 A network is a group of two or more computers linked together

There are many types of computer networks, including:

• local-area networks LAN : The computers are geographically close together  in the same building

• wide-area networks WAN : The computers are farther apart and are connected by telephone lines or radio waves.