LEDs or light emitting diodes are electronic semiconductor devices that give off red, green, yellow or blue light when an electric current is passed through them. It is also possible to obtain white light from blue LEDs by applying an internal luminescent coating.

The advantages of LEDs are long life, no maintenance, IR/UV-free light, low energy consumption, colour stability and shock resistance. LEDs are available in a range of designs.

Initially, LEDs were mostly used for orientation lighting. Then they played an increasing role both indoors and out as a source of dynamic lighting with RGB-mixed colours. Today, many desk lights and even the first street lights are available with LED technology. So it will not be long before the semiconductor crystals also invade the realm of general lighting as a source of white light.