Well, generically anyone who serves in the armed forces is a “soldier,” roughly speaking; though certainly that generic is broken down by branch of service. About the only branch that can claim a distinction is the Navy; yet, the Marines are part of the Navy, and they are more akin to the Army as far as mission than they are to the Navy.
I’m old school, and think the more appropriate term for anyone in the armed forces is “serviceman.” I was USAF, and I considered myself a serviceman. But then, as I said, I am old school.
Bullship. No MARINE would EVER consent to being called a soldier. Rifleman, perhaps, as all Marines are in a basic sense, but soldier? Hell no.
No comment.
Marines - Marine
Army - Soldier
Air Force - Airman
Navy Seabees are soldiers. Trained for combat as well as construction and demolition.