LED
Short for Light-Emitting Diode, LED is a special semiconductor that illuminates when an electrical charge passes through it. LEDs are commonly green or red; however can be an assortment of other colors. A good example of a LED is the led status indicators on your keyboard for Num lock, Caps lock and Scroll Lock, as shown in the
picture to the right. In this
picture the blue LED is lit on the keyboard to indicate the Num Lock is enabled.
Also see: Access light, Amber, Electronics definitions, Green, OLED, Orange, Red