The four types of market structures we study in economics are perfect competition, monopoly, oligopoly, and monopsony.

The overview according to the definition of the query is listed in the following part of the clarification.

Explanation:

Perfect rivalry or competition defines a business system in which a vast handful of similar competitors compete with homogeneous goods against each other. Monopolistic, respectively, refers to a business system where a vast number of individual companies compete with distinct goods against one another and. An Oligopoly defines a system of the economy where a limited number of businesses are competing against one another and. A monopoly depends on the business system where every other market is dominated by a single company.