In the field of inventory management, a stock keeping unit ( SKU ) is a distinct type of item for sale,William J. Sawaya, William C. Giauque, Production and operations management, Harcourt Brace Jovanovich, 1986, , p. 122. "Aspects of stock-keeping unit, or sku is an individually identifiable item stored in a specific location and tracked by an inventory system." such as a product or service, and all attributes associated with the item type that distinguish it from other item types. For a product, these attributes can include manufacturer, description, material, size, color, packaging, and warranty terms. When a business takes inventory of its stock, it counts the quantity it has of each SKU.
SKU can also refer to a unique identifier or code that refers to the particular stock keeping unit. These codes are not regulated or standardized. When a company receives items from a vendor, it has a choice of maintaining the vendor's SKU or creating its own.