This document discusses compact fluorescent lamps (CFLs). It states that CFLs use 1/5 to 1/3 the energy of incandescent lamps, last 8-15 times longer, and have higher upfront costs but lower lifetime electricity costs. CFLs contain mercury, emit light through phosphors, and come in integrated or non-integrated versions. They have longer lifespans than incandescent lamps and higher energy efficiency.