LED (Light Emitting Diode) - diode that emits light. In other words, a semiconductor device that converts electric current, passing through it, directly into light radiation. In the visible region it is perceived as a single color or monochrome. And the color of radiation is defined by both semiconductor materials and alloying additives.

The main LED part is an artificial semiconductor crystal, which can be red, yellow, green or blue. It is available in polished brass or aluminum cup that works both as a reflector and the cathode, and gold thread, welded to the crystal, plays the role of the anode. It is filled with transparent filler. It provides some form, which determines the angle of emission of light. The smaller the angle of radiation is, the more intense is the light output. It can be strengthened by changing the multilayer structure of the filler, as well as adding into the crystal special supplements and additives.