Books bar code printed of back cover of books and International Standard book Number (ISBN) of the books published formally have close relations.
正式出版的图书封底所印制的图书条形码与图书的国际标准书号(ISBN)有着密切的关系。
2
If you want the book to be categorized, either by a bookseller or a library, it has to be assigned a unique numerical code, like an ISBN, for International Standard book Number.