Monopoly

A situation in which a single company owns all or nearly all of the market for a given type of product or service. This would happen in the case that there is a barrier to entry into the industry that allows the single company to operate without competition(for example, vast economies of scale, barriers to entry,  or governmental regulation). In such an industry structure, the producer will often produce a volume that is less than the amount which would maximize social welfare.

Thus the main Characteristics of monopoly are: