Electric light bulbs are devices that produce light when electricity passes through them. They come in various types, including incandescent, fluorescent, and LED. Each type has different energy efficiency and lifespan characteristics, with LED bulbs being the most energy-efficient and long-lasting. The basic components of an electric light bulb include a glass enclosure, a filament or gas, and electrical contacts. When electricity flows through the filament in an incandescent bulb, it heats up and emits light. In fluorescent bulbs, gas inside the tube produces ultraviolet light, which then excites a coating on the inside of the glass to emit visible light.