Market definition requires that two separate markets be identified: the relevant product market and the relevant geographic market.
The relevant product market comprises all the products/services which the relevant consumer regards as interchangeable or substitutable by reason of the products’ characteristics, prices, and intended use.
The relevant geographic market, which may be national, international or sub-national, is the area in which an undertaking is involved in the supply and demand of products or services in which the conditions of competition are sufficiently homogeneous and which can be distinguished from neighboring areas because the conditions of competition are appreciably different in those areas.