Ambient light sensors are devices that detect the level of light in an environment. They are commonly used in smartphones, tablets, and other electronic devices to adjust screen brightness automatically, enhancing visibility and saving battery life. These sensors work by measuring the intensity of surrounding light and sending this information to the device's software. In addition to consumer electronics, ambient light sensors are also utilized in smart homes and buildings. They can control lighting systems, ensuring that artificial lights are only used when necessary, which contributes to energy efficiency and sustainability. Overall, these sensors play a crucial role in optimizing light usage in various applications.