The USDA defines bacon as "the cured belly of a swine carcass"; other cuts and characteristics must be separately qualified (e.g., "smoked pork loin bacon"). If bacon is USDA certified, then it has been treated for trichinella, a parasitic roundworm which can be destroyed by heating, freezing, drying, or smoking.

The names of rashers or slices differ depending on where they are cut from:

• Streaky bacon comes from the belly of a pig. It is very fatty with long veins of fat running parallel to the rind. This is the most common form of bacon in the United States. Pancetta is Italian streaky bacon, smoked or aqua (unsmoked), with a strong flavour. It is generally rolled up into cylinders after curing.
• Back bacon comes from the loin in the middle of the back of the pig. It is a lean meaty cut of bacon, with relatively less fat compared to other cuts and has a ham-like texture and flavour. Most bacon consumed in the United Kingdom is back bacon.^[6] Also called Irish bacon or Canadian Bacon.
• Middle bacon is much like back bacon but is cheaper and somewhat fattier, with a richer flavour.
• Cottage bacon is thinly sliced lean pork meat from a shoulder cut that is typically oval shaped and meaty. It is cured and then sliced into round pieces for baking or frying.
• Jowl bacon is cured and smoked cheeks of pork

Bacon joints include the following:

• Collar bacon is taken from the back of a pig near the head.
• Hock, from the hog ankle joint between the ham and the foot.
• Gammon, from the hind leg, traditionally "Wiltshire cured".
• Picnic bacon is from the picnic cut, which includes the shoulder beneath the blade.^[7] It is fairly lean, but tougher than most pork cuts.