A LED backlight LCD display, commonly called just an LED display, is one that uses LED bulbs instead of a fluorescent panel as the illumination for the screen. LED backlights are much thinner and consume less power than their traditional counterparts, and they can produce more vivid lighting effects.
LCD displays consist of a sheet of liquid crystal, a polarizing filter and some sort of backlight. A charge runs through the liquid crystal panel, altering the color at each pixel, and then the filtered light passes through, illuminating the image. Older LCD monitors use cold cathode fluorescent lamps for lighting, which produces an even light level across the entire panel. The polarizing filter and LCD pixels combine to darken areas of the screen to prevent the entire display from glowing a bright white.
There are two basic types of LED backlights. Full array backlights use a panel containing a large number of individual LED bulbs, and they can light certain sections of the panel selectively to produce strong contrasts between dark and light. Cheaper edge-lit arrays use a few LED bulbs arranged around the edge of the panel, and a series of light guides reflect this illumination across the entire panel.