LED (light emitting diode) is a semiconductor diode that emits incoherent narrow spectrum light when electrically biased in the forward direction of the p-n junction, as in common LED circuit.
Light emitting diodes are a reliable means of indication compared to light sources such as incandescent and neon lamps. LEDs are solid-state devices requiring little power and generating little heat. LEDs have the effect that is a from of electro luminescence.