Source : Free On-Line Dictionary of Computing

parent process
     
         The {Unix} {process} that created one or
        more other processes.
     
        Every process except process 0 is created when another process
        executes the {fork} {system call}.  The process that invoked
        fork is the parent process, and the newly created process is
        the {child process}.  Every process has one parent process,
        but can have many child processes.
     
        The {kernel} identifies each process by its {process
        identifier} (PID).  Process 0 is a special process that is
        created when the system boots; after forking a child process
        (process 1), process 0 becomes the {swapper} process.  Process
        1, known as {init}, is the ancestor of every other process in
        the system and enjoys a special relationship with them.
     
        (1997-12-03)