External security lights are essential for the security and design of not only business premises but also for residential, commercial, military and in institutional settings. The most common types of external security lights are floodlights and low pressure sodium vapour lights.

Some security light are automatic timers which are set to go on and off at only a particular time, others are light sensitive and works only from dusk to dawn while others are manually operated and goes on only when someone physically switches on a switch. These external security lights can either be powered by electricity or by solar energy. Most modern external security lights are fitted with a system of motion detection whereby they emit a beam of light that is detected by a photo-sensor located on the opposite end. When the beam of light is broken the photo-sensor will detect the change in the amount of light and ring an alarm. Other security lights are activated by sensors and only turn on when a person, or a mammal, approaches. However, external security lights are subject to vandalism and hence should be mounted very high, or else should be protected by a wire mesh or a polycarbonate shield.