A desktop session occurs between the time that you log in to the desktop and the time that you log out. The login screen, displayed by the Login Manager, is your gateway to the desktop. The login screen provides fields for you to enter your username and password. The Options menu on the login screen lists your login options, for example you can select the language of your session.
You start a session when you log in. The session manager starts after the Login Manager authenticates your username and password. The session manager enables you to manage the session. For example, you can save the state of your most recent session and return to that session the next time that you log in. The session manager saves and restores the following:
The appearance and behavior settings, for example fonts, colors, and mouse settings.
The applications that you were running, for example file manager and text editor windows. You cannot save and restore applications that the session manager does not manage. For example, if you start the vi editor from the command line in a terminal window, session manager cannot restore your editing session.