Back ribs are cut from where the rib meets the spine after the loin is removed. The upper ribs are called 'baby back ribs' not because they come from a baby pig! They're only called 'baby' because they are shorter in comparison to their bigger spareribs counterpart.
Baby back ribs have very tender meat and are in higher demand than St. Louis-style spareribs, so they have a higher price tag.
Name(s): Baby Back Ribs · Pork Loin Ribs