Active infrared is a technology that uses infrared light to detect objects or movement. It consists of an infrared light source and a sensor. The light source emits infrared beams, which reflect off objects and return to the sensor. When the sensor detects a change in the reflected light, it indicates the presence of an object or movement in the area. This technology is commonly used in security systems, such as motion detectors and alarm systems. It can also be found in automated lighting systems and remote controls. Active infrared systems are effective in various environments, providing reliable detection capabilities.