Definition: A socket represents a single connection between two network applications. These two applications nominally run on different computers, but sockets can also be used for interprocess communication on a single computer. Applications can create multiple sockets for communicating with each other. Sockets are bidirectional, meaning that either side of the connection is capable of both sending and receiving data.

Related Terms • IP • Nagle algorithm • port number

Programmers often use sockets in network programming, albeit indirectly. Programming libraries like Winsock hide many of the low-level details of socket programming. Sockets have been in widespread use since the early 1980s.

Also Known As: software object

Related Resources:

Introduction to Sockets
This article explains the basics of point-to-point socket communication, addressing and ports, and programming models.

Socket Programming Directory
Learn about the basics of socket programming through these useful online resources.