Modern CRTs are much less susceptible to burn-in than older models due to improvements in phosphor coatings, and because modern computer images are generally lower contrast than the stark green- or white-on-black text and graphics of earlier machines. LCD computer monitors, including the display panels used in
laptop computers, are not susceptible to burn-in because the image is not directly produced by phosphors (although they can suffer from a less extreme and usually non-permanent form of
image persistence). For these reasons, screensavers today are primarily decorative or for entertainment, and usually feature moving images or patterns and sometimes sound effects.