Spareribs are pork, of course, and are cut from the bottom section of the ribs and breastbone of the pig, just above the belly. (Baby back ribs are from the top of the rib area along the back.) With the removal of the bacon, a thin layer of meat remains on the spareribs. Spareribs are considered to be more meaty and succulent than baby back ribs. The slabs weigh between 2 and 5 pounds, with weightier slabs usually cut into smaller, more manageable racks.
Origin of the Term "Spareribs"
Obviously, the term spareribs does not refer to extra ribs. The term actually comes from the German Rippenspeer which literally translates to "spear ribs," as this cut was traditionally roasted on a spit or spear. In English, it became ribspare and eventually sparerib. This term not only refers to the practice of roasting the meat on a spear or spit, but it is a perfectly reasonable description of the cut itself, being spare of meat. You will see this cut referred to as spareribs (compound word) and spare ribs (two words), and both are equally acceptable.