Notebook and Portfolio

Notebook noun - A book with blank pages for recording notes or memoranda.

Portfolio and notebook are semantically related In some cases you can use "Portfolio" instead a noun "Notebook".

Portfolio noun - A large, flat, thin case for carrying loose papers or drawings or maps; usually leather.

Notebook and portfolio are semantically related in flat case for transporting papers topic. You can use "Notebook" instead a noun "Portfolio".