Some students are under the mistaken impression that the ISBN is used only to classify textbooks. However, this number is used in selling all kinds of books. People looking to get a price quote on a book or get more information about it can visit an ISBN database or any other book search website and look up a book by the ISBN – this interaction is known as ISBN search or ISBN lookup. ISBN search sites provide details of a book, including title, author, publisher, etc. If a person is interested in purchasing a book, the ISBN helps to find it.