Stupid Q - what's drop stepping?

Do you mean dropping your weight down a lot as you punch down - so no good for a short arse like me trying to aim for a taller guy's head?

As a shorter opponent would you ever really expect to be able to hit a taller opponent's head hard with a straight punch.

Taller people are my greatest weakness and it interfere's with how worthwhile I am as a sparring partner for many of my taller teammates - at least against guys my height I can be technically challenging but against the taller ones I've got nothing! (I'm still working on some great advice given RE fighting taller opponents so I'm really just wondering about the straights)