boards : Common term for the covers of a hardbound book.

dust jacket : A protective and often decorative wrapper, usually made of paper which wraps around the binding of a book.

octavo : A book whose page size is approximately 12 inches by 9 inches. The size is based on a sheet of paper 25 inches by 38 inches, the size of paper traditionally used by book printers, which has been cut into eight pages.

Cloth : Generally refers to a hardcover with cloth covering the outside of the book covers.