A downlight is a light fitting (luminaire) that lights in a downward direction to light an area below. They are usually recessed into the ceiling so you see only a small part of fitting below the ceiling. Downlights are wired on radial circuits which mean that they are all in a line. You will need to run the appropriate cable from the switch or ceiling rose to the first light, and then cable will be run on to the next light and so on until the last light in the circuit. Downlights are the all-purpose of lighting fixtures as they are used as a component of a good lighting plan in most lighting projects. A downlight is most often used to provide general lighting in a specific space.