This refers to the backlighting used by LCD TVs.

At present there are two main methods of backlighting in LCD flat-panels: Cold-Cathode Fluorescent Lamp (CCFL) and LED (light-emitting diode).
All locally available LED backlit LCD TVs use edge lit. Unless you're buying a direct LED back lit, you're paying extra money only for the ***iness.

http://www.lcdtvbuyingguide.com/hdtv/led-vs-lcd.html