A UPC (short for Universal Product Code) is a code used to mark retail product packaging for further identification of each particular item.
A EAN (short for European Article Number) is used to identify a product and its manufacturer. EAN is a superset of UPC (American standard).
ISBN (International Standard Book Number) is used as an identifier for commercial books. ISBNs are provided by affiliates of the International ISBN Agency. Each edition and variation of a book has its own unique ISBN.
GS1 is an organization that provides global standards for business communication. UPC (GTIN-12) is a unique number used to identify items and products in sales outlet. GTIN-14 is used for logistics purposes