textbook vs school text

textbook and school text both are nouns.

Word	Noun	Adjective	Verb	Adverb
textbook	Yes	Yes	No	No
school text	Yes	No	No	No

As nouns, textbook and school text are synonyms defined as:

textbook and school text: a book prepared for use in schools or colleges

Other synonyms of textbook include schoolbook, text, text edition.

textbook (noun)	school text (noun)
a book prepared for use in schools or colleges	a book prepared for use in schools or colleges

textbook (adjective)	school text (adjective)
according to or characteristic of a casebook or textbook; typical