Source : Free On-Line Dictionary of Computing

NetBIOS
     
        An {applications programming interface} (API) which activates
        {network} operations on {IBM PC} compatibles running under
        {Microsoft}'s {DOS}.  It is a set of network commands that the
        application program issues in order to transmit and receive
        data to another {host} on the network.  The commands are
        interpreted by a {network control program} or {network
        operating system} that is NetBIOS compatible.  See
        {NetBOLLIX}.