Product differentiation, either by style or by quality, is a business strategy with which consumers clearly perceive the company's own products differently from the products of the competitors. In this way companies gain more market power than in the case in which all products are homogeneous (as in the previous sections).
While perfect competition includes only homogeneous products and in the case of a monopoly there is only one differentiated product, an oligopoly may include both homogeneous and differentiated products.
Here you can download the programs for Cournot and Bertrand duopolies with product differentiation.