ROM vs storage

ROM and storage both are nouns.

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

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

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

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

ROM (noun)	storage (noun)
(computer science) memory whose contents can be accessed and read but cannot be changed	the commercial enterprise of storing goods and materials
	the act of storing something
	depositing in a warehouse
	a depository for goods
	an electronic memory device
	(computer science) the process of storing information in a computer memory or on a magnetic tape or disk