primer vs schoolbook

primer and schoolbook both are nouns.

Word	Noun	Adjective	Verb	Adverb
primer	Yes	No	No	No
schoolbook	Yes	No	No	No

As nouns, schoolbook is a hypernym of primer; that is, schoolbook is a word with a broader meaning than primer:

Other hypernyms of primer include school text, text, text edition, textbook.

primer (noun)	schoolbook (noun)
any igniter that is used to initiate the burning of a propellant	a book prepared for use in schools or colleges
the first or preliminary coat of paint or size applied to a surface
an introductory textbook