Apparently, Windows Server 2012 allows you to turn the GUI on and off. This is a bit similar to Server 2008, which had “Server Core”, a text-only environment. However, once you had installed Server Core, you were stuck with it – no going back to the GUI without wiping the machine and starting over.
-JM
ADDITIONAL READING:
Windows Server 2008 R2 Unleashed
Microsoft Windows Server 2008 R2 Administration Instant Reference