1) Book design 
The dust jacket (sometimes book jacket, dust wrapper or dust cover) of a book is the detachable outer cover, usually made of paper and printed with text and illustrations. This outer cover has folded flaps that hold it to the front and back book covers. Often the back panel or flaps are printed with biographical information about the author, a sum...
The paper cover (d.j.).
The loose (usually paper) wrap around a publication, designed to protect the main book from damage. Dust Jackets have come to be decorative finishes for many publications.