A Stock Keeping Unit, or SKU (pronounce either as an acronym (IPA: /ˈskjuː/) or as an initialism (/ˌɛsˌkeɪˈjuː/) “S–K–U”) is a unique identifier for each of the distinct products and services that can be ordered from a supplier. Usage of the SKU system is rooted in data management, enabling the merchant to systematically track their inventory, such as in warehouses and retail outlets.