Vibrate on screen tap
This feature, available only on some devices, enables vibration feedback on the lock screen.
Vibration feedback is sometimes known as Haptic feedback. The intention of haptic feedback is to add tactile feedback when a button is pressed, as a substitute for the sort of "click" feel that a physical button or key might have had, but touch screens do not have.
Haptic feedback can increase battery usage, and turning it off may improve battery life.