ISBNtunnistetta

ISBNtunnistetta, often referred to as an ISBN, is a unique commercial book identifier. It is a numeric commercial book identifier that is globally unique and unambiguous. The International Standard Book Number (ISBN) is a 13-digit number that is applied to books to distinguish them. Originally, ISBNs were 10 digits long, but due to the increasing number of books being published, they were expanded to 13 digits in 2007. The ISBN is used by publishers, booksellers, libraries, and bibliographic organizations to identify specific editions of a book.

The ISBN system was developed in the United Kingdom by David Whitaker and was first introduced in 1970. In 1972, the International Organization for Standardization (ISO) adopted it as an international standard. The ISBN is composed of five parts, separated by hyphens. The first part indicates the group or country of origin. The second part identifies the publisher. The third part is the publication number, unique to each title by a publisher. The fourth part is the check digit, which is used to verify the validity of the ISBN. The fifth part, added in the 2007 expansion, is the product code.

An ISBN is not a copyright or a legal identifier, but rather a unique product identifier. It allows for easier ordering, inventory control, and tracking of books. Libraries use ISBNs for cataloging and interlibrary loans. Booksellers use them for stocking and sales. Publishers use ISBNs for managing their publications. Each edition and format of a book, such as hardcover, paperback, or e-book, receives its own unique ISBN. This ensures that specific versions of a work can be accurately identified and differentiated.