The business model (not the market structure) of fast-food restaurants in the 1990s was that of chains, mostly formal and free chains. He belongs to monopolistic competition, i.e., a few manufacturers control the production and sale of products in the entire market of such a market organization, and there is no such thing as a semi-monopoly. Perfect competition is a market structure that is free from any hindrance or interference and refers to those markets in which there are no firms or consumers sufficient to influence prices. Its products are homogeneous and undifferentiated, there are a large number of vendors, and there is a buyer's market that determines prices, as in the case of the raw materials market (a number of unbranded agricultural products of similar quality). Monopolistic competition, oligopoly, monopoly (monopolistic competition and monopoly are not the same concept) are imperfect competition. Monopolistic competition products have certain differences (brand, quality differences), a large number of manufacturers, the seller has a certain ability to control prices, such as some light industry, retail catering industry. Oligopoly products do not necessarily have differences (e.g., oil companies), the number of vendors is several, and the seller has considerable ability to control prices, e.g., steel, automobiles, oil. Monopoly of the product is the only, no alternative products (do not use can not), the number of vendors is the only, there is a large degree of control over prices, such as tobacco, water and electricity, railroads and other public **** business.