The Accelerometer Sensor (often called ACCL in some contexts) is a sensor that detects changes in motion or orientation, typically in devices like laptops, tablets, and smartphones. It can measure acceleration along one or more axes (usually X, Y, and Z). This sensor is often used to detect device tilt, rotation, or movement, and can be used for features like auto-rotation of screens or for certain applications like gaming, fitness tracking, or even preventing hard drive damage by detecting sudden movement.