Lighting is an essential part in our lives. It can bring us not only visibility but also comfort, convenience and security. Since ancient times, people have employed various lighting sources to make their living more enjoyable. Today, lighting takes the form of electric lights and has become an integral part of our lives. From night lights to turning on all the lights when we walk into a room, electric lights are in use almost everywhere. It is difficult to imagine a life without lights. Electric lights also play an important role in our security system. The right kind of lighting can discourage crime and increase people's sense of security. Security lighting can be used to immediately turn on lights when someone passes by, warning off any trespassers. Lighting can also give us a sense of warmth and comfort. Warm lighting gives a feeling of friendliness and welcome, while cool lighting reflects a feeling of efficiency and tasking. The ability to change the look and feel of a room by controlling the lighting is invaluable. Lighting, both natural and artificial, has come a long way since its humble beginnings. It has made our lives easier and more comfortable. We are able to live and work in a safe and secure environment, and enjoy the beauty and warmth of light.