This is an ISBN from the exclusive U.S. agent for issuing International Standard Book Numbers (ISBNs), a universal method of identifying books in print, R.R. Bowker. Bowker is the publisher of Books in Print and other compilations of information about books and periodical titles. It provides supply chain services and analytical tools to the book publishing industry. Each version of a book requires a differnt ISBN (paperback, ebook, hardback, differrent editions, etc.). An ISBN is not generally required for eBooks, though many dsitributors require one. The ISBN will be registered to the publisher in the name of the author and title of the book; no right are given up by the author: the ISBN is merely a uniquer identifier connecting the book to the author and the publisher.