It is a concept used to enable customers to select a function in determining the specifications of the product, by which the customers specify products and parts incorporated into the final product in determining the final product, where products or parts incorporated are selected from a group whose individual element has the identical property. By using this concept, it is possible to deal with the diversification of product. The similar concept to Option is Variant. Customers arbitrarily select Option, while they must select Variant.

Taking the purchase of car as an example, a car stereo system is an option and the customer don't have to select it if he or she don't want it, but if a tire is selectable, you must select either one, e.g., standard tire, radial tire, or other tire. This selection type is usually called Variant.

Related term: Variant