XC: Smooth terrain, minimal technical obstacles, Fast and flowy.
AM: Rockier terrain and steeper descents means that you may have to actually move behind your seat a little bit. On the climbs you may have to lift up your front tire here and there.
AAM: You will have to get behind your seat. You will have to use brakes and body motions to make it down large obstacles and trail sections. Everything on the trail can be rolled. On the climbs you may have to lift up your front and lunge up very high steps.
DH/FR/BD: Same as AAM, but you may have to leave the ground, hit jumps, drops etc to make it down the trail. Climbs? You may have to sprint and clear a sick double.