Here is a short explanation of the different kinds of hard binding and the materials used. Case or edition binding, the most common type of binding for hardcover books, involves sewing the individual signatures together, flattening the spine, applying endsheets and a strip of cloth to the spine. Then the hard covers are attached.
Some of the materials used for hard bound books are cloth, buckram, paper products, and leather. Until the mid-20th century, covers of mass-produced books were laid with cloth, but from that period onwards, most publishers adopted clothette, a kind of textured paper which vaguely resembles cloth but is easily differentiated on close inspection. Buckram is a stiff cloth that is often coated with acrylic and is a very durable cover. Clothette and other paper products are very common and can be made to look like imitation leathers or given linen textures. These are quite durable and cost effective. Leather is rarely used because it is challenging to work with and very expensive.
If you are still confused with some of the book binding terms, here is a great glossary of bookbinding words.
Here is a link to my post last year about book binding that you might like to read.