"Baby back ribs
Baby back ribs, sometimes called loin ribs or simply back ribs, are taken from the top of the rib cage between the spine and the spareribs, below the loin muscle. They have meat between the bones and are shorter but meatier than spareribs. 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" (7.6 cm) and the longest is usually about 6" (15.2 cm), depending on the size of the hog. Whilst a pig has 15 ribs, a rack of baby back ribs contains a minimum of 8 ribs but can include up to 15 ribs depending on how it has been prepared by the butcher."