The term originally came 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 or spare ribs. The name did not come from the Bible, as at least one of you was thinking.
Spareribs are cut from the bottom section of the ribs and breastbone of the pig, just above the belly and include 11 to 13 long bones. Baby back ribs are from the top of the rib area along the back. Spareribs are considered to be more meaty and succulent than pork baby back ribs.
In Western cooking spare ribs are generally cooked on a barbecue or on an open fire, and are served as a slab (bones and all) with a thick barbecue type sauce. St. Louis style ribs are trimmed and have the brisket bone removed, while Kansas City-style ribs are trimmed even further, and have the hard bone removed.