Relations of Computer Networks

Peer-to-peer (P2P) is a decentralized communications model in which each node has the same capabilities and either node can initiate a communication session. Unlike the client/server model, in which the client makes a service request and the server fulfills the request, the P2P network model allows each node to function as both a client and server.

does not need fileserver 

Client and Server 

Although the client/server model can be used by programs within a single computer(SERVER), it is a more important concept for networking.  In this case, the client establishes a connection to the server over a local area network (LAN) or wide-area network (WAN), such as the Internet or Local Cabling, Once the server has fulfilled the client's request, the connection is terminated. Your Web browser is a client program that has requested a service  from a server; in fact, the service and resouce the server provided is the delivery of this Centralized sharing resource through fileserver

Comunication Pantners 
Sender :- Transfer the Requested Sharing Resources to Receivers Segment
Receivers :- Receiving Sharing Data Form Sender form Sender
Media:- Linked the Sender and Receiver Segment
Protocols:- Controlling and Manage Connections and Communication
Messages:- Sharing Resources and also called as Network  Resources