Case:

The Case is made up of the bookboards, the binding, and the spine.  The bookboards cover the front and back of the book and is usually covered with fabric.  The binding is connected to the front and back bookboards.  The spine, which is not seen, is positioned between the binding and the pages.

Book Block:

The Book Block is made up of the signatures, the endleaves, the mull, and the headbands.  The signatures, which make up the signature-set, are most of the pages in a book.  They are held together with thread.  The endleaves are the front and back pages of a book.  They are glued to the bookboards and the signature-set.  The mull is a meshed fabric that is glued around the signature-set to hold them tightly in place.  The mull flaps are glued to the inside of the bookboards.  The headbands are the decorative pieces that are glued to the top and bottom  the mull.