Description about display manager

There is a configuration file called /etc/sysconfig/desktop. This file defines default display manager and desktop name.

Display manager can be any one of the following:
[a] gnome (gdm)
[b] kde (kdm)
[c] xdm (xdm)

Desktop can be any one of the following
[a] KDE
[b] GNOME
[c] XFCE

Specifying GNOME as a display manager will invoke GDM.

Upon boot, the system will run /etc/init/prefdm.conf which will in turn call the "Preferred Display Manager" (prefdm) script /etc/X11/prefdm which will utilize the settings in /etc/sysconfig/desktop if available.