oratorio vs cantata

oratorio and cantata both are nouns.

Word	Noun	Adjective	Verb	Adverb
oratorio	Yes	No	No	No
cantata	Yes	No	No	No

As nouns, oratorio and cantata are synonyms defined as:

oratorio and cantata: a musical composition for voices and orchestra based on a religious text

oratorio (noun)	cantata (noun)
a musical composition for voices and orchestra based on a religious text	a musical composition for voices and orchestra based on a religious text