The Global Trade Identification Number is synonymous with 8- and 13-digit bar code.
The EAN or better: GTIN numbers contain the issuing country and a reference to the manufacturer as well as a serial product number and a check digit. The numbers are assigned worldwide by GS1.
The Proof GmbH is a member of GS1.
An article with tips for creating GTIN numbers for graphic designers can be found here. (German)