This tool allows a user to be automatically logged into the system at boot time, without a password being required.
Here are the available parameters:
If you wish to have the X Window System (graphical display) started at boot time, check the Launch the graphical environment when your system starts box. If you leave it unchecked, the text login will be displayed and you will need to start the graphical environment manually.
If you're the only person using your machine and nobody else has access to it, you may choose to be automatically logged in at boot time.