What function does an ambient light sensor typically serve in laptops?

An ambient light sensor in laptops primarily serves to regulate the backlit keyboard illumination. This sensor detects the level of ambient light in the environment and adjusts the brightness of the keyboard backlight accordingly. In low-light conditions, for instance, the sensor will increase the brightness of the keyboard backlights to improve visibility, making it easier for users to see the keys. Conversely, in well-lit settings, it may reduce or turn off the backlight to conserve battery life and avoid unnecessary brightness. This automatic adjustment enhances user experience by ensuring that the keyboard remains easy to use regardless of the lighting conditions around the device.