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

spine : The outer portion of a book which covers the actual binding. The spine usually faces outward when a book is placed on a shelf. Also known as the back.

gilt : Decorative patterns imbedded into the affected portion of a book. Often appears on the boards or the spine, and may be very simple, to elegant, to ludicrous.

8vo : Short for Octavo, A book whose page size is approximately 8-10 inches tall. 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 folded and cut into 16 pages.. Unfortunately often misunderstood to mean 8 volumes.

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