I love them both!!!  Both Al Pastor and Carnitas are made with pork but the difference lies in the preparation and seasonings. Carnitas is made with pork shoulder and is Mexico’s version of pulled pork.  It is seasoned with oregano, garlic, cumin, onion, jalapeno and orange juice and braised until fall-apart tender.  The shredded pork is then oven-roasted until slightly crispy. Authentic Al Pastor, on the other hand, is spit-roasted pork and seasoned with guajille chiles, achiote paste, pineapple juice, etc.   It is thinly sliced vertical shavings of caramelized pork served with pineapple.