A meatball is a generally spherical mass of ground meat and other ingredients, such as bread or breadcrumbs, minced onion, various spices, and possibly eggs, cooked by frying, baking, steaming, or braising in sauce.
A faggot is a kind of meatball, a traditional dish in the UK, especially the southwest of England, Wales, and the Black Country. It's made from meat off-cuts and offal, especially pork.