fixed storage vs ROM

fixed storage and ROM both are nouns.

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

As nouns, fixed storage and ROM are synonyms defined as:

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

Other synonyms of fixed storage include read-only memory, read-only storage.

fixed storage (noun)	ROM (noun)
(computer science) memory whose contents can be accessed and read but cannot be changed	(computer science) memory whose contents can be accessed and read but cannot be changed