possession vs keeping

possession and keeping both are nouns.

Word	Noun	Adjective	Verb	Adverb
possession	Yes	No	No	No
keeping	Yes	No	No	No

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

possession (noun)	keeping (noun)
anything owned or possessed	the responsibility of a guardian or keeper
the act of having and controlling property	conformity or harmony
(sport) the act of controlling the ball (or puck)	the act of retaining something
the trait of resolutely controlling your own behavior
a territory that is controlled by a ruling state
a mania restricted to one thing or idea
being controlled by passion or the supernatural