Source : Free On-Line Dictionary of Computing

Inter-process Communication
     
         (IPC) Exchange of data between
        one {process} and another, either within the same computer or
        over a {network}.  It implies a {protocol} that guarantees a
        response to a request.  Examples are {Unix} {sockets}, {RISC
        OS}'s messages, {OS/2}'s {Named Pipes}, {Microsoft Windows}'
        {DDE}, {Novell}'s {SPX} and {Macintosh}'s IAC.
     
        Although IPC is performed automatically by programs, an
        analogous function can be performed interactively when users
        cut and paste data from one process to another using a
        {clipboard}.
     
        (1995-12-14)