The combination (under the management of one firm) of two or more identical (horizontal) or successive (vertical) stages in the production or marketing process of a particular product. Generally the stages are capable of being operated as separate businesses. The firm that has management responsibility is called the integrator. The poultry industry, for example, is vertically integrated, from production through processing and distribution. Diversification, on the other hand, is the production of two or more products by one firm or farmer.