Lighting can be defined as any form of visible radiation or illumination that makes things visible. There are different types of lighting that are used for different purposes. It can be used to illuminate a dark room, to create atmosphere or to define a certain mood. Indoor lighting is important for activities such as working, cooking, reading and simply having a general feeling of comfort. Overhead, recessed, wall-mounted, and under-counter lights, as well as task lights, are some of the common types of indoor lighting. Ceiling fans with lights, table or floor lamps, spotlights, and track lighting can make up the lighting options in an indoor setting. Outdoor lighting is primarily used for security, decorative and practical purposes. Examples of outdoor lighting fixtures include wall-mounted floodlights, hanging pendants, sconces and post-mounted lights. Motion detectors, timers, and solar-powered lights can also be used to ensure maximum efficiency. Safety and nighttime visibility are key functions of roadway and street lighting. Typically, streetlights are mounted to poles that are placed along the street to illuminate the area and make it easier to see during times of darkness. Luminaires, or light fixtures, are mounted to the poles to provide the correct distribution of light. No matter what type of lighting is being used, its important to consider the wattage, style and color temperature when selecting fixtures. Additionally, many types of lighting fixtures require the use of compatible bulbs to provide optimal light output. By making the right choices when selecting lighting fixtures, it is possible to create a desired atmosphere and lighting effect.