A screensaver is an application that replaces the image on a screen when the screen is not in use. The screensaver application for the GNOME desktop is XScreenSaver. The following sections describe how to set preferences for the XScreenSaver application, and how to modify the displays that are available for the screensaver.

	Note
	The XScreenSaver application does not allow you to lock your screen if you are logged in as root. If you want to be able to lock your screen, log in as a normal user. To obtain system administrator privileges, open a terminal window, then use the su command to log in as root.