Source : Free On-Line Dictionary of Computing

network segment
     
         A part of an {Ethernet} or other network, on
        which all message traffic is common to all nodes, i.e. it is
        broadcast from one node on the segment and received by all
        others.  This is normally because the segment is a single
        continuous conductor, though it may include {repeaters}(?).
     
        Since all nodes share the physical medium, {collision
        detection} or some other {protocol} is required to determine
        whether a message was transmitted without interference from
        other nodes.  The receiving node inspects the destination
        address of a {packet} to tell if it was (one of) the intended
        recipient(s).
     
        Communication between nodes on different segments is via one
        or more {routers}.
     
        (1996-10-16)