U. S. Army vs armed forces

U. S. Army and armed forces both are nouns.

Word	Noun	Adjective	Verb	Adverb
U. S. Army	Yes	No	No	No
armed forces	Yes	No	No	No

U. S. Army (noun)	armed forces (noun)
the army of the United States of America; the agency that organizes and trains soldiers for land warfare	the military forces of a nation