What is the primary purpose of the International Standard Book Number (ISBN)?

The primary purpose of the International Standard Book Number (ISBN) is to provide a unique identifier for books and other media. Each ISBN is a distinct numeric code that allows for the precise identification of a specific edition of a book, which is crucial for sales, distribution, inventory management, and tracking. This standardization aids publishers, booksellers, libraries, and readers alike in easily locating and ordering the correct items among the potentially vast array of available titles.

While classifying books by genre, measuring sales, and indexing library catalogues are all important aspects of book management and dissemination, they do not represent the fundamental role that the ISBN plays in the publishing and bookselling ecosystem. The unique identifier is what enables accurate referencing and communication about a specific version of a title in a global context.