Function

• LCD televisions and monitors simply use a backlight to illuminate the liquid crystals that make up the screen. This is why LCD sets are much thinner than CRT sets, which project an image onto the inside of the screen.
  
  

Differences

• Traditional Cathode Ray Tube (CRT) televisions and monitors use more energy than a similarly sized LCD because the entire picture is produced by blasting electrons on chemical phosphors. The difference in energy consumption is estimated to be about 75 percent less in an LCD.
  
  

Considerations

• LCD energy consumption is not static; it is affected by many factors. Larger screens require more power to illuminate and therefore use more energy. Brighter images also require more illumination, and power consumption can be reduced by lowering the default screen brightness. Many TVs have an auto dimmer that reduces brightness when no activity is detected, which reduces energy consumption.