armed services vs armed forces

armed services and armed forces both are nouns.

Word	Noun	Adjective	Verb	Adverb
armed services	Yes	No	No	No
armed forces	Yes	No	No	No

As nouns, armed services and armed forces are synonyms defined as:

Other synonyms of armed services include military, military machine, war machine.

armed services (noun)	armed forces (noun)
the military forces of a nation	the military forces of a nation