memory vs engram

memory and engram both are nouns.

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

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

memory: something that is remembered
engram: a postulated biochemical change (presumably in neural tissue) that represents a memory

Other hyponyms of memory include reminiscence, recollection, memory trace, confabulation, screen memory.

memory (noun)	engram (noun)
an electronic memory device	a postulated biochemical change (presumably in neural tissue) that represents a memory
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