selective service vs conscription

selective service and conscription both are nouns.

Word	Noun	Adjective	Verb	Adverb
selective service	Yes	No	No	No
conscription	Yes	No	No	No

As nouns, selective service and conscription are synonyms defined as:

Other synonyms of selective service include draft, muster.

selective service (noun)	conscription (noun)
compulsory military service	compulsory military service