"The Cold Cathode Fluorescent Light (CCFL) is one of the newest forms of CFL. CCFLs use electrodes without a filament. The voltage of CCFL lamps is about 5 times higher than CFL lamps and the current is about 10 times lower. CCFL lamps have a diameter of about 3 millimeters. The lifetime of CCFL lamps is about 50,000 hours. The lumens per watt is about half of CFL lamps.
Initially CCFL was used for thin monitors and backlighting, but **now it is also manufactured for use as a lightbulb.** Since the efficacy (watt/lumen) is actually lower than a compact fluorescent light, it is actually not as efficient as a CFL. Its advantages are that it is (1) instant-on, like an incandescent, (2) compatible with timers, photocells, and dimmers, and (3) has an amazingly long life of approximately 50,000 hours. CCFL are a convenient transition-technology for those who are not comfortable with the short lag-time associated with the initial lighting of Compact Fluorescents. They are also an effective and efficient replacement for lighting that is turned on and off frequently with little extended use (e.g. a half-bath or closet)."** Emphasis mine
-- Bobby G.