Gammon is the hind leg of pork after it has been cured by dry-salting or brining,which may or may not be smoked. Strictly speaking, a gammon is the bottom end of a whole side of bacon (which includes the back leg), ham is just the back leg cured on its own. Like bacon, it must be cooked before it can be eaten; in that sense gammon is comparable to fresh pork meat, and different from dry-cured ham like prosciutto.