Programs that communicate with the X server are called X clients.
Most of these programs will ask the X server to display windows on
the screen.
You start an X client the same way you start any other Debian
program. Simply type the name of the client on the command line. Try
typing xterm into an existing xterm window, and a new xterm client
will appear on the screen.
You may notice that the original xterm is now useless, because your
shell is waiting for the second xterm to finish. To avoid this
problem, you can run the X client in the backgroundby adding a &
after the command name like this: xterm &. If you forget, you can
place a running process in the background. First suspend the process
with CTRL-z, and then place it in the background with the bg
command.
If you use a program often, your window manager will generally
provide a way to put that program on a convenient graphical menu.