possibility vs possible

possibility and possible both are nouns.

Word	Noun	Adjective	Verb	Adverb
possibility	Yes	No	No	No
possible	Yes	Yes	No	No

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

possibility (noun)	possible (noun)
a tentative insight into the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena	something that can be done
a possible alternative	an applicant who might be suitable
a future prospect or potential
capability of existing or happening or being true

possibility (adjective)	possible (adjective)
	capable of happening or existing
	existing in possibility