Client Server Processes
A network application consist of pairs of process that send message to one another over a network. For example in a web application a client browser process exchanges messages with a web server process. For each pair of communicating processes were typically label one of the two processes as the client and the another process as the server. With the web a browser is a client process and a web server sea server process. With P2P file sharing the peer that is downloading the file is labelled as the client and the peer that is uploading the file is labelled as the sever.
We defines the client and server processes as follow;
In the context of a communication session between a pair of processes the process that initiates the communication is labelled as the client. The process that waits to be contacted to begin the session to the server.