在国际贸易中一个国家提供某种产品比提供其它产品更为便宜合算，这就是由于各国间提供同一产品的成本不同而形成的比较利益。这种由比较优势而形成的比较利益不仅广泛存在于国际贸易领域，而且在一国内部不同地区。不同企业之间广泛存在并发生作用，支配着生产分工和商品交换 In international trade, it is cheaper and more cost-effective for a country to provide a product than other products, which is due to the comparative advantage resulting from the different costs of providing the same product among countries. This comparative advantage formed by comparative advantages not only exists widely in the field of international trade, but also in different parts of a country. The widespread existence and role of different enterprises govern the division of labor and the exchange of goods