Computer networks can have different designs, with the two basic forms being client/server and peer-to-peer networks. Client/server networks have centralized servers for storage, which are accessed by client computers and devices.
Peer-to-peer networks are often used for file sharing and communication between computers. The main advantage of using a P2P network is its ability to provide high availability and fault tolerance. If one computer in the network goes down, others can continue working as if nothing happened.

More info : Computer Network