Unix domain socket
A Unix domain socket or IPC socket (inter-process communication socket) is a data communications endpoint for exchanging data between processes executing on the same host operating system. Like named pipes, Unix domain sockets support transmission of a reliable stream of bytes (SOCK_STREAM, compare to TCP). In addition, they support ordered and reliable transmission of datagrams (SOCK_SEQPACKET), or unordered and unreliable transmission of datagrams (SOCK_DGRAM, compare to UDP). The Unix domain socket facility is a standard component of POSIX operating systems.