screen saver

noun Computers.
  1. a program that displays a constantly shifting pattern on a screen when the computer is idle, originally used to prevent damage to the screen through continuous display of the same image but now used primarily for decoration.
Also screen·sav·er [skreen-sey-ver] /ˈskrinˌseɪ vər/
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018