An Ambient Light Sensor is a device that detects the level of light in an environment. It measures the intensity of surrounding light and adjusts the brightness of screens or lighting systems accordingly. This helps improve visibility and conserve energy by ensuring that lights are only as bright as needed. These sensors are commonly found in smartphones, tablets, and smart home devices. By using an Ambient Light Sensor, devices can automatically dim or brighten displays based on the amount of natural light available, enhancing user experience and reducing eye strain.