What does MAC (or any) powder for your face do?

Well I don't really use 'foundation'.


More like MAC Studio Skin Finish, but I can consider it as that.What does MAC (or any) powder for your face do?
sets your makeup n helps it stay longer.


usually people use powder to set it when after they use fluid foundation.What does MAC (or any) powder for your face do?
Foundation w out powder?!? Now that is crazy talk! Lol well at least it is to me lol...sets your makeup and totally helps from streaky, greasy skin...ewww.
if sets your foundation and concealer.aka it helps it stay in place.