prosecuting officer vs DA

prosecuting officer and DA both are nouns.

Word	Noun	Adjective	Verb	Adverb
prosecuting officer	Yes	No	No	No
DA	Yes	No	No	No

As nouns, DA is a hyponym of prosecuting officer; that is, DA is a word with a more specific, narrower meaning than prosecuting officer:

prosecuting officer: a government official who conducts criminal prosecutions on behalf of the state
DA: an official prosecutor for a judicial district

Other hyponyms of prosecuting officer include district attorney, state's attorney, state attorney.

prosecuting officer (noun)	DA (noun)
a government official who conducts criminal prosecutions on behalf of the state	an official prosecutor for a judicial district