retention vs module

retention and module both are nouns.

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

As nouns, module is a hypernym of retention; that is, module is a word with a broader meaning than retention:

Other hypernyms of retention include faculty, mental faculty.

retention (noun)	module (noun)
the act of retaining something	a self-contained component (unit or item) that is used in combination with other components
the power of retaining liquid	computer circuit consisting of an assembly of electronic components (as of computer hardware)
the power of retaining and recalling past experience	detachable compartment of a spacecraft
	one of the inherent cognitive or perceptual powers of the mind