A product variant is an item grouped with related variants that together form a product. Variants usually vary from each other in one or more properties. For example, a medium-sized, green shirt with a stock-keeping unit (SKU) of 14678 is one product variant of the Shirt product; together size, color, and SKU form one variant. A product variant always includes a unique identifier, such as an SKU, and a price. Each product variant is based on the same product definition.