cantata vs oratorio

cantata and oratorio both are nouns.

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

As nouns, cantata and oratorio are synonyms defined as:

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

cantata (noun)	oratorio (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