The Global Trade Item Number or GTIN is a unique identifier for over the global market trade items developed by GS1. This identifier is a number that is created by and belongs to a retailer, distributor, etc. This number usually has a barcode that can be scanned to pull up the item in the database and are used to look up product information in a database which may belong to a retailer, manufacturer, collector, researcher, or other entity. GTINs may be 8, 12, 13 or 14 digits long and is unique to each and every item to differentiate items from each other.