what is a cfl bulb

A CFL bulb, or compact fluorescent lamp, is a type of fluorescent lamp designed to replace incandescent light bulbs. They rely on gas reactions inside their tubes to produce light, and the internal ballast system sends a current through the tube to excite the gases, which emits ultraviolet light. The fluorescent coating absorbs the UV rays and emits visible light. CFLs are highly energy efficient, using up to 75% less energy than incandescent bulbs, and have a longer lifespan. They are produced for both alternating current (AC) and direct current (DC) . While the purchase price of a CFL is typically 3–10 times greater than that of an equivalent incandescent lamp, a CFL lasts 8–15 times longer and uses two-thirds to three-quarters less energy. CFLs can be used to replace higher-power incandescent lamps than justified by their light output, but equivalent wattage claims can be replaced by comparison of actual light output emitted by the lamp, which is measured in lumens and marked on the packaging.