Network Programming with Perl

Clients, Servers, and Protocols

Network communication occurs when two programs exchange data across the net. With rare exceptions, the two programs are not equal. One, the client, initiates the connection and is usually, but not always, connected to a single server at a time. The other partner in the connection, the server, is passive, waiting quietly until it is contacted by a client seeking a connection. In contrast to clients, it is common for a server to service incoming connections from multiple clients at the same time.

Although it is often true that the computer ("host") that runs the server is larger and more powerful than the client machine, this is not a rule by any means. In fact, in some popular applications, such as the X Windows ...