This is more just because i am intrigued. There are two ways of clicking, a tap click, where just just tap the touchpad, and a click click, where you physically push it down, so it goes 'click'. I generally use tap click (just because its slightly easier). I came to notice a difference when on the website TED. If you want to watch a video in full screen you can click the 'toggle full screen' button. But this only works if you click it with a 'click click' and not with a 'tap click'. But why is the end command of a 'tap click' different to a 'click click', i.e. why can the website tell the difference?