operative vs NOC

operative and NOC both are nouns.

Word	Noun	Adjective	Verb	Adverb
operative	Yes	Yes	No	No
NOC	Yes	No	No	No

As nouns, NOC is a hyponym of operative; that is, NOC is a word with a more specific, narrower meaning than operative:

operative (noun)	NOC (noun)
someone who can be employed as a detective to collect information and assist in criminal investigations	an undercover agent who is given no official cover
a person secretly employed in espionage for a government

operative (adjective)	NOC (adjective)
being in force or having or exerting force
relating to or requiring or amenable to treatment by surgery especially as opposed to medicine
(of e.g. a machine) performing or capable of performing
effective; producing a desired effect