Server has no GUI, that's the big difference between the desktop edition and
the server edition. You can install Gnome or KDE, but the assumption its
that it is neither necessary nor desirable for routine server operations.

GUI's consume CPU cycles and reduce stability. That's why Microsoft Servers
were never as stable as Novel's in the days when I worked as a net admin, 10
years ago.

The old Novel servers were legendary for their stability, often sitting with
neither keyboard nor monitor attached. One is reported to have sat untouched
for four years giving perfect service and only rebooted when the power went
off.