network socket

A network socket is one endpoint in a communication flow between two programs running over a network.

Sockets are created and used with a set of programming requests or "function calls" sometimes called the sockets application programming interface (API). The most common sockets API is the Berkeley UNIX C interface for sockets. Sockets can also be used for communication between processes within the same computer.

This is the typical sequence of sockets requests from a server application in the connectionless context of the Internet in which a server handles many client requests and does not maintain a connection longer than the serving of the immediate request:

socket()
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bind()
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recvfrom()
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(wait for a sendto request from some client)
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(process the sendto request)
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sendto (in reply to the request from the client...for example, send an HTML file)

A corresponding client sequence of sockets requests would be:

socket()
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bind()
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sendto()
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recvfrom()

Sockets can also be used for "connection-oriented" transactions with a somewhat different sequence of C language system calls or functions.

The Secure Sockets Layer (SSL) is a computer networking protocol that manages server authentication, client authentication and encrypted communication between servers and clients.