possibility vs possible action

possibility and possible action both are nouns.

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

As nouns, possibility and possible action are synonyms defined as:

Other synonyms of possibility include opening.

possibility (noun)	possible action (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	a possible alternative
a possible alternative
a future prospect or potential
capability of existing or happening or being true