Mouse acceleration
Also called enhance pointer precision · pointer acceleration
Mouse acceleration moves the cursor further when you move the mouse quickly than when you move it the same distance slowly. Windows calls it Enhance pointer precision and turns it on by default.
In practice
Acceleration makes a fast flick travel further than a slow movement over the same distance. It helps on a small desk with a large screen. It makes aiming harder in games because the same hand movement doesn’t always move the same distance. Many gamers turn it off and many office users never notice it is on.
How to check
In Windows, open the Control Panel mouse settings, go to Pointer Options and look for Enhance pointer precision. On a Mac it’s controlled by the tracking speed setting and some mouse software. Turn it off and move the mouse the same distance slowly and then quickly. The cursor should travel the same distance both times.