memory vs mental representation

memory and mental representation both are nouns.

Word	Noun	Adjective	Verb	Adverb
memory	Yes	No	No	No
mental representation	Yes	No	No	No

As nouns, mental representation is a hypernym of memory; that is, mental representation is a word with a broader meaning than memory:

memory: something that is remembered
mental representation: a presentation to the mind in the form of an idea or image

Other hypernyms of memory include internal representation, representation.

memory (noun)	mental representation (noun)
an electronic memory device	a presentation to the mind in the form of an idea or image
the power of retaining and recalling past experience
the cognitive processes whereby past experience is remembered
something that is remembered
the area of cognitive psychology that studies memory processes