The login screen displayed by the login server is an attractive alternative to the traditional character-mode login screen and provides capabilities beyond those provided by a character-mode login.
As with a character mode login, the user enters a user name followed by a password. If authenticated, the login server starts a desktop session for the user. When the user exits the desktop session, the login server displays a new login screen, and the process begins again.
To customize the login screen, you can:
Change the login screen appearance
Configure X server authority
Change the default language
Issue commands prior to display of the login screen
Change the contents of the login screen Language menu
Specify the command to start the user's session
Issue commands prior to the start of the user's desktop session
Issue commands after the user's session ends
Each of these can be done for all displays or on a per-display basis.