Meat processors take fabrication step by step. It starts with a side of meat, which is a half. The next processing is quarters followed by the primal cuts. The primal cuts are cut into subprimals and then retail cuts. You may see whole subprimals at a retail store that you can further break down at home, but rarely the actual primal cuts.
Here are a couple of charts that detail the basic retail cuts and the bone groups. The picture of the seven basic retail cuts of meat shows a side of beef, but you can substitute lamb or veal here. Pork is slightly different on the bottom, but essentially the same.
Images courtesy National Live Stock and Meat Board.