1 - Understand product IDs

Unique product identifiers are a series of numeric or alphanumeric characters, which correspond to the barcode assigned to the product. They are used to identify and recognize a given item.
The product identifiers correspond to a unique barcode allowing to find products online. They are usually the Global Trade Item Number (GTIN), the Manufacturer Part Number (MPN) and the brand name.

• The GTIN is used to identify items globally. And the importance of the GTIN is precisely this international character.
• The MFN is an alphanumeric value assigned by the manufacturer. It is used to identify a product among all those of the manufacturer. An MFN is required for all products that do not have a manufacturer-assigned GTIN. The only exceptions are custom products or those that simply do not have a clearly defined MPN.