Monopoly is one type of entertainment game which is played in personal computer or laptop. It exists when a specific individual or an enterprise has sufficient control over a particular product or service to determine significantly the terms on which other individuals shall have access to it. A monopoly must be distinguished from monopsony, in which there is only one buyer of a product or service. A monopoly may also have monopsony control of a sector of a market. Likewise, a monopoly should be distinguished from a cartel in which several providers act together to coordinate services, prices or sale of goods. Monopolies can form naturally or through vertical or horizontal mergers. A monopoly is said to be coercive when the monopoly firm actively prohibits competitors from entering the field.