A Unixsystem call used by a process (the "pareNT") to make a copy (the "child") of itself. The child process is ideNTical to the pareNT except it has a differeNTprocess ideNTifier and a zero return value from the fork call. It is assumed to have used no resources. A fork followed by an exec can be used to start a differeNT process but this can be inefficieNT and some later Unix variaNTs provide vfork as an alternative mechanism for this. See also fork bomb. (1996-12-08)