paperback
A book with a soft, bendable paper cover.
A paperback is a book with a soft, flexible cover made of thick paper or cardboard, as opposed to a hardcover book, which has rigid boards covered in cloth or leather. Paperbacks bend easily, fit in backpacks without adding much weight, and cost less to produce and buy.
Publishers often release popular books in hardcover first, then issue a paperback edition a year or so later at a lower price. This makes books more accessible to readers who can't afford or don't want the more expensive version. You'll find paperbacks everywhere: in school book fairs, library shelves, beach bags, and coat pockets.
The paperback revolution began in the 1930s when publishers realized they could print quality books cheaply enough for almost anyone to afford. Before that, books were luxury items. Paperbacks democratized reading, letting millions of people build personal libraries. Today, hardcovers don't cost that much more than paperbacks to produce, but publishers still charge substantially more for them.
Some readers prefer paperbacks because they're portable and casual (you can toss one in your bag without worry). Others prefer hardcovers for their durability and the substantial feel of holding them. Both have their place, but paperbacks have helped make books part of everyday life.