## Overview#

International Standard Book Number (ISBN) is a numeric Unique Identifier for commercial books represented as an EAN.International Standard Book Number is assigned to each edition and variation (except reprintings) of a book. For example, an ebook, a paperback, and a hardcover edition of the same book would each have a different International Standard Book Numbers.

International Standard Book Number is 13 digits long if assigned on or after 1 January 2007, and 10 digits long if assigned before 2007.

An International Standard Book Number consists of 4 parts (if it is a 10 digit ISBN) or 5 parts (for a 13 digit ISBN). The parts of a 10-digit ISBN and the corresponding EAN‑13 and barcode. Note the different check digits in each. The part of the EAN‑13 labeled "EAN" is the Bookland country code.

- Prefix element (for a 13-digit ISBN) - a GS1 Company Prefix: so far 978 or 979 have been made available by GS1
- Registration group element– this identifies the particular country, geographical region, or language area participating in the ISBN system. This element may be between 1 and 5 digits in length
- Registrant element - this identifies the particular publisher or imprint. This may be up to 7 digits in length
- Publication element – this identifies the particular edition and format of a specific title. This may be up to 6 digits in length
- Check Digit – this is always the final single digit that mathematically validates the rest of the number. It is calculated using a Modulus 10 system with alternate weights of 1 and 3.

### More Information#

There might be more information for this subject on one of the following:- [#1] - International_Standard_Book_Number - based on information obtained 2017-10-28-
- [#2] - What is an ISBN? - based on information obtained 2018-09-07-