memory vs retrieval

memory and retrieval both are nouns.

Word	Noun	Adjective	Verb	Adverb
memory	Yes	No	No	No
retrieval	Yes	No	No	No

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

memory (noun)	retrieval (noun)
an electronic memory device	the act of regaining or saving something lost (or in danger of becoming lost)
the power of retaining and recalling past experience	the cognitive operation of accessing information in memory
the cognitive processes whereby past experience is remembered	(computer science) the operation of accessing information from the computer's memory
something that is remembered
the area of cognitive psychology that studies memory processes