What term describes a market condition where only one seller dominates?

The term that describes a market condition where only one seller dominates is "monopoly." In a monopoly, the single seller has significant control over the market, including price setting, supply, and availability of the product or service. This dominance often leads to a lack of competition, which can impact consumer choice and market dynamics.

In a monopolistic market, barriers to entry are typically high, preventing other potential competitors from entering the market. This can result in inefficiencies, as the monopolist may not have the same incentives to innovate or improve their offerings compared to a competitive market, where multiple sellers vie for consumer interest. Consequently, the idea of a monopoly is crucial in understanding market structures and their implications for economic welfare and consumer benefits.

The other market structures mentioned reflect different competitive scenarios. A duopoly involves two dominant sellers, an oligopoly consists of a few sellers, and perfect competition features many sellers with no single entity dominating the market. Each of these structures has its own characteristics and implications for market behavior and consumer experience.