A touchpad is not a mouse, or at least not a good one

Things like straightforward mouse pointer tracking and left button clicks are not all that different between the two and so I can mostly treat things the same (although I think that moving more or less purely vertically or horizontally is harder on a touchpad). What is increasingly different on a touchpad is things like right or middle clicks, and moving the mouse pointer while a nominal button is ‘down’. And of course there’s no such thing as chorded mouse clicks on a touchpad, while at the same time a mouse button has no real equivalent of multi-finger movement and swiping.

Source: utcc.utoronto.ca