Hornbook and Textbook

Hornbook noun - A primer that provides instruction in the rudiments or basic skills of a branch of knowledge.

Textbook and hornbook are semantically related. In some cases you can use "Textbook" instead a noun "Hornbook".

Textbook noun - A book used for instruction in a subject.

Hornbook and textbook are semantically related. Sometimes you can use "Hornbook" instead a noun "Textbook".