screen saver

In computing, program designed to prevent a static image from ‘burning’ itself into the phosphor screen of an idle computer monitor. If the user leaves the computer alone for more than a few minutes, the screen saver automatically displays a moving or changing image – perhaps a sequence of random squiggles, or an animation – on the screen. When the user touches any key, the computer returns to its previous state. Screen savers can be password protected, so that unauthorized users cannot access the machine in the operator's absence.