DISPLAY NAMES

       From the user's perspective, every X server has a  display
       name of the form:

                  hostname:displaynumber.screennumber

       This  information  is used by the application to determine
       how it should connect to the server and  which  screen  it
       should  use  by  default  (on displays with multiple moni-
       tors):

       hostname
               The hostname specifies the name of the machine  to
               which the display is physically connected.  If the
               hostname is not given, the most efficient  way  of
               communicating to a server on the same machine will
               be used.

       displaynumber
               The phrase "display" is usually used to  refer  to
               collection  of  monitors  that share a common key-
               board and pointer  (mouse,  tablet,  etc.).   Most
               workstations  tend  to only have one keyboard, and
               therefore, only one display.   Larger,  multi-user
               systems, however, frequently have several displays
               so that more than one person can be doing graphics
               work at once.  To avoid confusion, each display on
               a machine is assigned a display number  (beginning
               at  0)  when  the  X  server  for  that display is
               started.  The display number must always be  given
               in a display name.

       screennumber
               Some  displays share a single keyboard and pointer
               among two or more monitors.   Since  each  monitor
               has  its  own  set  of  windows,  each  screen  is
               assigned a screen number (beginning at 0) when the
               X  server  for  that  display  is started.  If the
               screen number is not given, screen 0 will be used.

       On  POSIX  systems,  the default display name is stored in
       your DISPLAY environment variable.  This variable  is  set
       automatically  by  the  xterm terminal emulator.  However,
       when you log into another machine on a network,  you  will
       need to set DISPLAY by hand to point to your display.  For
       example,

           % setenv DISPLAY myws:0
           $ DISPLAY=myws:0; export DISPLAY