Most smoked pork butt recipes call for a bone-in pork shoulder, sometimes also labeled a Boston butt roast or a pork butt. All of these labels are for the exact same cut of pork. None of them actually come from the butt end of the pig (which can definitely be confusing), but from the upper part of the shoulder. The pork butt, or pork shoulder, has many overlapping and hard working muscle groups that are bound together with tight connective tissue.
That tight tissue makes this cut particularly well suited for smoking. It would be very difficult to simply slice and serve a pork shoulder roast that wasn’t cooked low and slow to break down those tight muscles and connective fibers. You’d end up chewing for a long time and not getting anywhere. By using the low and slow process of cooking the meat over a wood fire for a long time, those tissues begins to break down, tenderize, and create amazing strands of super succulent smoked pork shoulder.