The standard "white powder" stuff is the cocaine hydrochloride salt. Crack is the free base "pure" amine, which makes it more accessible for the body. As a result the high hits faster and harder but also doesn't last nearly as long as with "regular" cocaine. So 5-10 minutes after you smoke some, you get a pretty nasty crash and the craving for another hit of crack...
The standard "white powder" stuff is the cocaine hydrochloride salt. Crack is the free base "pure" a