Incandescent bulbs are the standard type of bulbs that were most common till some years back. incandescent light bulbs are made of glass, and are round in shape. They work by heating a tungsten filament, or wire, until it glows. This is what produces the light that you see. Unfortunately, 90% of the energy used to generate that light is wasted as heat, making incandescent bulbs a very inefficient way to light your home.
instead of a glowing filament, CFLs contain argon and mercury vapor housed within a tube curved in different shapes. When an electric current passes through the mixture, the gas gets excited, and it produces ultraviolet light. The ultraviolet light, in turn, stimulates a fluorescent coating painted on the inside of the tube. As this coating absorbs energy, it emits visible light.
CFLs last a longer time than incandescent bulbs. In some tests, they burned brightly for 10,000 hours, whereas standard bulbs burned for just 800 to 1500 hours. CFLs use significantly less energy - 75 percent less energy than incandescent light bulbs. This means that by using CFLs, you are not only saving electricity, but also helping the environment by reducing energy consumption and preventing greenhouse gas emissions that contribute to global climate change.