LED LCD backlight is a small strip of light or light source that is located inside a display, TV or monitor to illuminate the screen. All LED TVs are LCD panels with LED backlighting. A common misconception is that LED displays are different from LCD, while they are essentially the same. LED can better be described as a subset of LCD devices.

LCD is an acronym for Liquid Crystal Display, a type of monitor or screen (and flat panel technology) that relies on thousands or millions of pixels arranged in a rectangular grid. When an LCD is turned on, each pixel has a red, green, or blue subpixel (RGB) that is either turned on or off. When the pixels are turned off, the individual portion appears black, and when all the subpixels are turned on, it appears white. Collectively, the arrayed pixels create the sharp image on the screen by being in an on or off configuration.

LED backlighting illuminates the pixels from behind, making them appear richer and brighter. Not all LCDs have backlighting, and not all LCDs that do use LED backlighting. Some displays also use CCFL lighting, or Cold-Cathode Fluorescent Lamps. Although, it should be noted that CCFL displays are being phased out in favor of LED-backlit panels.

The liquid crystals in an LCD panel do not need any illumination themselves and require light from a separate component. In this case, this is provided by the LED backlight.