Marginal cost refers to the cost of producing one additional unit of a good or service. It is the cost of producing the last or extra unit of output.
This cost includes the variable costs of producing the additional unit, such as the cost of materials and labor, but it does not include fixed costs like rent or salaries, which do not change with the level of production.
The concept of marginal cost is important in economics because it helps businesses and policymakers make decisions about how much to produce, what price to set for their goods or services, and whether to enter or exit a market. By analyzing their marginal costs, businesses can determine whether producing an additional unit of a good will be profitable or not.