A product is a single item in a Web site catalog. Products are not necessarily a physical item, such as a book; they can also be a service, such as renewing your vehicle registration.
Define a product through a combination of property definitions. Think about your product types, and find the attributes that are common for the product type and use them as the basis of your product definition. For example, if you have a product definition named Soccer Shirts, which has the properties Name, Color, and Size, you create a product for each name, color, and size combination for Soccer Shirts that you want to include in your catalog.
A product family is a product that contains product variants. A product family is not distinct from a product in any other way. A product family always includes a unique identifier, such as the product name. After you define your products, you decide which products require product variants. A product variant is a specific item that is grouped with related variants that, together, form a product. Product variants usually vary from each other in one or more properties. If each variation of a product requires its own stock-keeping unit (SKU), you should probably define product variants. For example, a medium-sized, green shirt with a SKU of 14678 is one product variant of the Shirt product; together, the size, color, and SKU form one variant. A product variant always includes a unique identifier, such as a SKU, and a price. Each product variant is based on the same product definition