1. Bootcamp. You're learning all the basics, from history to troop movement, and basic weapons qualification.

2. Infantry Training Battalion. A primer on top of bootcamp for navigation, shooting, troop movement, and weapons qualification. (These are required of every Marine in order to join "The Fleet")

3. Primary/Secondary school. This is your a-billet training (your primary job).

Where most of the other training occurs is once you're in the fleet, which occurs in your first unit after Step 3. There's a moderately high attrition baseline to get to the fleet, which signifies a minimally deployable Marine.