An International Standard Book Number (ISBN) is a unique numeric commercial book identifier which is intended to be used in conjunction with the title to identify a specific book edition and binding. ISBNs are used by publishers, booksellers, libraries, and other parties in the supply chain to identify, locate, order, and track books.
ISBNs were first developed in the United Kingdom in 1966. The International Organization for Standardization (ISO) adopted ISBN as an international standard in 1970. The current version of the ISBN standard is ISO 2108:2017.