What are fluorescent lights and how do they differ from other types of lighting?

Fluorescent lights are a type of lighting that use electricity to excite Mercury vapor, which then produces ultraviolet light that causes a phosphor coating inside the bulb to glow and emit visible light. They differ from other types of lighting, like incandescent bulbs, in that they are more energy efficient and produce less heat, but they can have a flickering effect and contain small amounts of mercury which can be harmful if not disposed of properly.