Coherent light is a term used to describe light in which all waves are in phase, such as the light produced by a laser.
Felt (fabric) is the name of a unique textile fabric made of a random fibrous material classified according to a type of manufacture.
A light-emitting diode (LED) is a term used on a light source beneficial, energy-saving replacement of the traditional light bulb. LED is a semiconductor device in which monochromatic light produced as electrons undergo a transition across the bandgap.
A photovoltaic cell ( solar cells) is a term used to describe devices that convert solar radiation directly to electricity. PV’s are a sort of semiconductor that catches the light and turn into pure and clean power. These devices are sound and smoke-free, no moving parts.