LED or Light Emitting Diode
LED is the acronym for Light Emitting Diode.
An LED, when turned on, emits a small amount of light.
A computer keyboard usually has at least three LEDs.
One for Num Lock
One for Caps Lock
One for Scroll Lock
The computer may also contain some LEDs to indicate the status of the computer.
An LED may produce red, green, blue, yellow, white, or even infrared light. They use a fairly small amount of electricity compared to an incandescent light, but they use more electricity than a Liquid Crystal Display.
Some flashlights use an LED instead of a regular light bulb. Flashlights that use LEDs have a very long battery life.