Baby back ribs (or loin ribs, back ribs) are taken from the top of the rib cage between the spine and the spare ribs, below the loin muscle. The designation "baby" indicates the cuts are meat between the bones and on top of the bones, and are shorter, curved, and sometimes meatier than spare ribs. The rack is shorter at one end, due to the natural tapering of a pig's rib cage. The shortest bones are typically only about 3 in (7.6 cm) and the longest is usually about 6 in (15 cm), depending on the size of the hog. A pig side has 15 to 16 ribs (depending on the breed), but usually two or three are left on the shoulder when it is separated from the loin. So, a rack of back ribs contains a minimum of eight ribs (some may be trimmed if damaged), but can include up to 13 ribs, depending on how it has been prepared by the butcher. A typical commercial rack has 10–13 bones. If fewer than 10 bones are present, butchers call them "cheater racks".
 

Spare ribs also called "spareribs" or "side ribs", are taken from the belly side of the rib cage, below the section of back ribs and above the sternum (breast bone). Spare ribs are flatter and contain more bone than meat, but more fat can make the ribs more tender than back ribs. The origin of the name "spare ribs" is not certain, but could be related to the spare amount of meat after the belly is removed.
 

St. Louis cut ribs (or St. Louis cut spare ribs) are St. Louis style when the sternum bone, cartilage, and rib tips have been removed. The shape is almost rectangular.
 

Rib tips are short, meaty sections of rib attached to the lower end of the spare ribs, between the ribs and the sternum. Unlike back ribs or spare ribs, the structure of the rib is provided by dense costal cartilage, not bone. Rib tips are cut away from the spare ribs when preparing St. Louis style spare ribs.|
 

Spare ribs also called "spareribs" or "side ribs", are taken from the belly side of the rib cage, below the section of back ribs and above the sternum (breast bone). Spare ribs are flatter and contain more bone than meat, but more fat can make the ribs more tender than back ribs. The origin of the name "spare ribs" is not certain, but could be related to the spare amount of meat after the belly is removed.
 

Rib roast (or bone-in pork loin rib roast, bone-in loin rib roast, center cut rib roast, prime rib of pork, standing rib roast) is a whole pork loin with the back ribs attached. They can be up to 2 ft long and 6 in thick. They are sold whole or in sections.
 

Country ribs are cut from the blade end of the loin close to the pork shoulder. They are meatier than other rib cuts. They contain no rib bones, but are instead contain parts of the shoulder blade (scapula).