read-only memory vs ROM

read-only memory and ROM both are nouns.

Word	Noun	Adjective	Verb	Adverb
read-only memory	Yes	No	No	No
ROM	Yes	No	No	No

As nouns, read-only memory and ROM are synonyms defined as:

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

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

read-only memory (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