The paperback type of book is presented with a thick paper or paperboard cover and is often held together with glue rather than stitches or staples. In contrast, hardcover or hardback books are bound with cardboard covered with cloth, plastic, or leather. The pages on the inside of a paperback are made of paper.
Inexpensive books bound in paper have existed since at least the 19th century in such forms as pamphlets, yellowbacks, dime novels, and airport novels. Modern paperbacks can be differentiated by size. 

In the U.S., there are “mass-market paperbacks” and larger, more durable “trade paperbacks”. In the U.K., one can find A-format, B-format, and the largest C-format sizes. Paperback editions are issued when a publisher decides to release a book in a low-cost format. Cheaper, lower-quality paper, glued (rather than stapled or sewn) bindings, and the lack of hardcover may contribute to the lower cost of paperbacks. Paperbacks can be the preferred medium when a book is not expected to be a major seller or the publisher wishes to release a book without putting forth enormous investment. Examples include many novels and newer editions or reprintings of older books. 

Since paperbacks tend to have a smaller profit margin, many publishers try to balance the profit by selling fewer hardcovers against the potential earnings by selling more paperbacks with a smaller profit per unit. First editions of many modern books, especially genre fiction, are issued in paperback. Best-selling books, on the other hand, may maintain sales in hardcover for an extended period, to reap the greater profits that the hardcovers provide. 

We love the smell of printed paper and the sound of browsing pages. However, we cannot deny the practical side of e-books. Taking your book collection, or even a few of your favorites, with you while on holiday can be voluminous when your e-reader can connect you with a hundred online libraries.
Mainly, we buy e-books for their good price, followed by the increased comfort, as you can purchase from home or on the go with mobile devices, and of course, for the extensive selection of titles.