keeping vs retention

keeping and retention both are nouns.

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

As nouns, keeping and retention are synonyms defined as:

Other synonyms of keeping include holding.

keeping (noun)	retention (noun)
the responsibility of a guardian or keeper	the act of retaining something
conformity or harmony	the power of retaining liquid
the act of retaining something	the power of retaining and recalling past experience