LED televisions often provide superior black levels and better energy efficiency than traditional LCD or plasma televisions. LED televisions are also often thinner and lighter than other types of televisions, and some models can reproduce colors more accurately than other types of displays.
Despite their name, LED televisions use the same liquid crystal display technology as LCD televisions. However, LED televisions use light-emitting diodes to back-light the image on the LCD display, while older LCD televisions use a compact fluorescent bulb. LEDs are smaller than fluorescent bulbs, so LED TVs can be lighter and thinner than comparable LCD televisions. This is often accomplished by placing the LEDs around the edge of the television rather than directly behind the LCD display.
It is also possible to use multiple independent LEDs to back-light a television, allowing the LEDs that illuminate darker portions of an image to independently dim relative to LEDs lighting brighter areas. This technique is known as local dimming. Local dimming improves the black levels of dark areas in images over traditional LCDs, which often display very dark regions as lighter than intended due to light leaking from their single backlight. Some high-end LED televisions use individual red, green and blue LEDs to light their displays, allowing those models to use local dimming to improve color reproduction as well.