Tender vs. less tender meats. This can be a big subject but really it boils down to just a couple of simple concepts. If a muscle gets a lot of exercise in an animal it will be a less tender cut of meat. So the meat that comes from the front shoulder or hind end of either a cow or pig will be a less tender cut as as those animals do a LOT of walking around. Pork chops and beef steaks generally come from the rib or mid section of the animal. That area gets much less exercise than a leg or neck. Muscles that see little exercise are considered tender cuts.
The less tender cuts will be more flavorful than a tender cut or meat but require a bit of careful cooking to make a delicious meal. Less tender cuts must be cooked at a low temperature (325-350 degrees F), with moisture (but not necessarily a lot of liquid) and for a longer period of time than a tender cut. This is why the less tender cut of meat called stew meat makes a delicious meal. The same recipe made with sirloin steak would not be as flavorful.
The less tender cuts tend to be less expensive than the tender cuts. Just remember to plan a bit more time in your meal preparation to make the meat tender and delicious.