Motion sensor lights are lighting devices that automatically turn on when they detect movement within a certain range. They use infrared sensors to sense heat emitted by people or animals, making them useful for security and convenience. These lights can be installed outdoors or indoors, providing illumination when needed without the need for manual switches. These lights are energy-efficient, as they only activate when someone is present, helping to reduce electricity costs. Many models also come with adjustable settings, allowing users to customize the sensitivity and duration of the light. This makes motion sensor lights a practical choice for homes and businesses alike.