First, you should know that all LED TVs are also LCD TVs, the “LED” refers only to the type of lighting source used to illuminate the LCD pixels in the television. Confusing matters even more, is the fact that there is more than one way to light the pixels. The two major technologies are edge-lit and full-array.
The latter term refers to televisions that use a full panel of LEDs to illuminate the pixels. Most of these sets also have local dimming, which means the LEDs can be dimmed in different regions of the panel simultaneously, helping to improve black levels and picture uniformity. Edge-lit, on the other hand, means the LEDs that illuminate the pixels are located only on the edges of the set.
In general, full-array LED is considered a superior technology when it comes to picture quality, but edge-lit sets have one major advantage: depth. Edge-lit LED TVs can be much thinner than those lit with either a full LED panel or traditional fluorescent (non-LED) backlights. For that reason, most of the super-thin sets you see in stores will be edge-lit.
Which technology is right for you? That depends.
If you’re looking for the best possible picture quality, you are most likely to find it in a full-array LED display with local dimming. If, on the other hand, you are primarily concerned about the appearance of the television and want a set that is extremely thin, edge-lit is your best friend.