handbook vs book of facts

handbook and book of facts both are nouns.

Word	Noun	Adjective	Verb	Adverb
handbook	Yes	No	No	No
book of facts	Yes	No	No	No

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

handbook: a concise reference book providing specific information about a subject or location
book of facts: a book to which you can refer for authoritative facts

Other hypernyms of handbook include reference, reference book, reference work.

handbook (noun)	book of facts (noun)
a concise reference book providing specific information about a subject or location	a book to which you can refer for authoritative facts