Light Emitting Diodes (LED) are semi-conductors - a type of electrical component. They have been around since the early 1960s when they were used as indicator lights on electrical components. The first ones emitted a low intensity red light, yellow LED was invented a decade later, followed by the first high-brightness, high-efficiency LED.
As the technology evolved, other colours became available, light output increased, efficiency and reliability improved.
There are now many types of LEDs and they come in all different shapes and sizes. However, it was the development of high-power white light LED that led to its use in illumination and lighting. Today LEDs are fast replacing traditional incandescent bulbs and compact fluorescent lamps (CFL) as lighting sources.
