possible vs realizable

possible is a noun but realizable is not a noun.

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

possible (noun)	realizable (noun)
something that can be done
an applicant who might be suitable

possible (adjective)	realizable (adjective)
capable of happening or existing	capable of existing or taking place or proving true; possible to do
existing in possibility	capable of being realized