An electric light is a device that produces visible light by the flow of electric current.It is the most common form of artificial lighting and is essential to modern society, providing interior lighting for buildings and exterior light for evening and nighttime activities.efore electric lighting became common in the early 20th century, people used candles, gas lights, oil lamps, and fires. Most electric lighting is powered by centrally generated electric power, but lighting may also be powered by mobile or standby electric generators or battery systems.