A program creates a pipe with the pipe() function. A pipe typically sends data from one process to another; the two ends of a pipe can be used in a single program task. A pipe does not have a name in the file system, and it vanishes when the last process that is using it closes it.

A program creates a socket with the socket() function. A socket is a method of communication between two processes that allows communication in two directions, in contrast to a pipe, which allows communication in only one direction. The processes using a socket can be on the same system or on different systems in the same network.