Fluorescent bulbs are energy-efficient lighting devices that use a gas-filled tube to produce light. When electricity passes through the gas, it emits ultraviolet light, which then excites a phosphor coating inside the bulb, creating visible light. These bulbs are commonly used in homes, offices, and schools due to their long lifespan and lower energy consumption compared to traditional incandescent bulbs. Fluorescent bulbs come in various shapes and sizes, including tube lights and compact fluorescent lamps (CFLs). They are available in different color temperatures, allowing users to choose the type of light that best suits their needs. However, they contain a small amount of mercury, which requires careful disposal.