ROM vs memory

ROM and memory both are nouns.

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

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

ROM: (computer science) memory whose contents can be accessed and read but cannot be changed
memory: an electronic memory device

Other hypernyms of ROM include computer memory, computer storage, memory board, storage, store.

ROM (noun)	memory (noun)
(computer science) memory whose contents can be accessed and read but cannot be changed	an electronic memory device
	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