Marine vs military personnel

Marine and military personnel both are nouns.

Word	Noun	Adjective	Verb	Adverb
Marine	Yes	No	No	No
military personnel	Yes	No	No	No

As nouns, military personnel is a hypernym of Marine; that is, military personnel is a word with a broader meaning than Marine:

Marine: a member of the United States Marine Corps
military personnel: someone who serves in the armed forces; a member of a military force

Other hypernyms of Marine include man, military man, serviceman.

Marine (noun)	military personnel (noun)
a member of the United States Marine Corps	soldiers collectively
	someone who serves in the armed forces; a member of a military force