Bacon is usually pork belly or back that has been cured or brined, seasoned, and often smoked. There are countless variations - sliced thick or thin, center-cut, precooked, microwavable, and made from turkey or other meats. Aside from convenience or alternative bacons, here are a few styles you're likely to encounter in supermarkets and specialty stores:
1 Irish and English bacon. Taken from the loin, with lean surrounded by a ring of fat. Cured and/or smoked.
2 Canadian bacon. Precooked, very lean, cured and lightly smoked, and cut from the loin. (Known as "back bacon" in Canada.)
3 Country bacon. Often heavily smoked, salty, and thickly sliced.
4 Standard bacon. Sliced and packaged, usually with the rind trimmed.
5 Pancetta. Italian bacon from the belly that is seasoned, dry-aged, and cured - not smoked.
6 Slab bacon. Pork belly with fat, lean, and rind, that has been cured and/or smoked, but not sliced.