In economics, an export is any good or commodity, transported from one country to another country in a legitimate fashion, typically for use in trade. Export is an important part of international trade. Its counterpart is import. The theory of comparative advantage materialized during the first quarter of the 19th century in the writings of 'classical economists'. While David Ricardo is most credited with the development of the theory. The theory states that all parties maximize benefit in an environment of unrestricted trade, even if absolute advantages in production exist between the parties. In economics, an import is any good (e.g. a commodity) or service brought into one country from another country in a legitimate fashion, typically for use in trade. Import goods or services are provided to domestic consumers by foreign producers. An import in the receiving country is an export to the sending country.