trio vs three

trio and three both are nouns.

Word	Noun	Adjective	Verb	Adverb
trio	Yes	No	No	No
three	Yes	Yes	No	No

As nouns, trio and three are synonyms defined as:

trio and three: the cardinal number that is the sum of one and one and one

trio (noun)	three (noun)
a musical composition for three performers	one of four playing cards in a deck having three pips
three people considered as a unit	the cardinal number that is the sum of one and one and one
a set of three similar things considered as a unit
three performers or singers who perform together
the cardinal number that is the sum of one and one and one

trio (adjective)	three (adjective)
	being one more than two