Answer:
There are many kinds from snipers to infantry to air force. Each and everyone of them are in the USMC. Plus, there are different types of Army, Navy, and Air Force.The list can go on and on. But in the marines you have to go through several steps such as a 14 week workout plan at the base, plus writing, which you must pass. In return you get more training but better results than the army and more high-tech equipment.