Correction to last post
It's close, but not quite.
Ham comes from the rear leg of the pork carcass, and Canadian bacon comes from the loin, an area that originates just behind the shoulder and travels along the backbone to the hip region. Regular bacon is from the belly -- which explains why it contains more fat. And "picnic ham" comes from the lower portion of the front leg. All of these cuts are cured -- a method of preserving meat that changes its flavor, color and texture. But only ham is "ham." Ironically, "Canadian bacon" isn't called "Canadian bacon" in Canada. It's called back bacon.
Continue: Is ham the poorman's beef ?