A light sensor is a device that detects the presence and intensity of light in its environment. It converts light energy into an electrical signal, allowing it to measure brightness levels. Common types of light sensors include photodiodes, phototransistors, and light-dependent resistors (LDRs). These sensors are widely used in various applications, such as automatic lighting systems, cameras, and smartphones. Light sensors play a crucial role in enhancing energy efficiency and user experience. For example, in smart homes, they can automatically adjust indoor lighting based on natural light levels. In cameras, they help optimize exposure settings for better image quality.