Sex with the woman on top; she kneeling over the man. If she's facing the same direction as the man then that's the "cowgirl position". If she's facing the other way (towards the man's feet) then that's the "reverse cowgirl position".

This is one of the favorite sexual positions in porn; perhaps because it makes it easier to film the woman as she's not obscured by some porn stud's big, hairy ass.