rolls

Rolls are when the board is parallel to the boat. Going the same direction. Flips are when your board is perpidicular to the boat. End over end. I get this. But when doing a back roll do your heels lead the rotation? What I mean by that is do your heels face the sky. Or do your toes face the sky. Im almost positive its your heels, but whats it called when you do it the other way. Ohter way meaning toes to the sky. Probably a frontroll...right? If so then why does a toeside backroll lead with the toes. I understand if it lead with the heels it would be a frontroll. Why is it so confusing. Somebody please shed some light on the subject for me. And how do you do a hs front roll? Is it what i was saying earlier with the toes to the sky?