Which component is commonly used in a mouse to sense movement?

A light sensor is commonly used in a mouse to sense movement, particularly in optical mice. These mice use a laser or LED light to illuminate the surface beneath them. The light reflects back into a sensor, which captures images of the surface. By comparing these images rapidly, the mouse can determine how far and in which direction it has moved.

The reliance on light sensors allows for high accuracy and responsiveness, making them suitable for a wide variety of surfaces. In contrast, pressure sensors measure force, magnetic field sensors detect changes in magnetic fields, and temperature sensors monitor heat levels—none of which directly relate to tracking movement in the same effective way as light sensors do in a mouse.