yearbook vs reference book

yearbook and reference book both are nouns.

Word	Noun	Adjective	Verb	Adverb
yearbook	Yes	No	No	No
reference book	Yes	No	No	No

As nouns, reference book is a hypernym of yearbook; that is, reference book is a word with a broader meaning than yearbook:

Other hypernyms of yearbook include book of facts, reference, reference work.

yearbook (noun)	reference book (noun)
a reference book that is published regularly once every year	a book to which you can refer for authoritative facts
a book published annually by the graduating class of a high school or college usually containing photographs of faculty and graduating students