front matter vs prelims

front matter and prelims both are nouns.

Word	Noun	Adjective	Verb	Adverb
front matter	Yes	No	No	No
prelims	Yes	No	No	No

As nouns, front matter and prelims are synonyms defined as:

front matter and prelims: written matter preceding the main text of a book

front matter (noun)	prelims (noun)
written matter preceding the main text of a book	written matter preceding the main text of a book