Source : Free On-Line Dictionary of Computing

packet switching
     
         A communications paradigm in which {packets}
        (messages or fragments of messages) are individually {routed}
        between {nodes}, with no previously established communication
        path.  Packets are routed to their destination through the
        most expedient route (as determined by some routing
        {algorithm}).  Not all packets travelling between the same two
        hosts, even those from a single message, will necessarily
        follow the same route.
     
        The destination computer reassembles the packets into their
        appropriate sequence.  Packet switching is used to optimise
        the use of the {bandwidth} available in a network and to
        minimise the {latency}.  {X.25} is an international standard
        packet switching network.
     
        Also called {connectionless}.  Opposite of {circuit switched}
        or {connection-oriented}.  See also {virtual circuit},
        {wormhole routing}.
     
        (1999-03-30)