Quick Guide to GNOME Display Manager (GDM)
The GNOME Display Manager (GDM) is a program that facilitates graphical user login for Linux systems using GNOME, running and managing the X.Org display servers for both local and remote logins. The GNOME Display Manager (GDM) is the login graphical user interface (GUI) and manager for the GNOME desktop environment within Linux. GDM runs in the background and is a replacement for X Display Manager (XDM), handling user authentication, and initiating desktop sessions.