Zustand: Good. Item in good condition. Textbooks may not include supplemental items i.e. CDs, access codes etc.
Zustand: Acceptable. A readable copy. All pages are intact, and the cover is intact (However the dust cover may be missing). Pages can include considerable notes--in pen or highlighter--but the notes cannot obscure the text. Book may be a price cutter or have a remainder mark.
Zustand: Very Good. Very Good condition. A copy that may have a few cosmetic defects. May also contain light spine creasing or a few markings such as an owner's name, short gifter's inscription or light stamp.