facultative vs optional

facultative and optional both are adjectives.

Word	Noun	Adjective	Verb	Adverb
facultative	No	Yes	No	No
optional	No	Yes	No	No

facultative (adjective)	optional (adjective)
able to exist under more than one set of conditions	possible but not necessary; left to personal choice
of or relating to the mental faculties
granting a privilege or permission or power to do or not do something
optional