Final answer:
Barriers to entry are legal, technological, or market forces that prevent competitors from entering a market and competing with a firm. They can include things like economies of scale, control of resources, and legal restrictions. One example of a barrier to entry is a patent.
Step-by-step explanation:
Barriers to entry are the legal, technological, or market forces that prevent potential competitors from entering a market. These barriers can include economies of scale, control of a physical resource, legal restrictions, and practices like predatory pricing. They serve to protect a firm's advantage and prevent rivals from competing away its advantages. One example of a barrier to entry is a patent, which provides exclusive rights to a product or idea for a specific period of time.