International trade occurs because different countries produced by the cost. A country that can produce a specific type of product with low cost. When compared with other countries, countries that are manufacturers and through other sales. Note that the items are produced with different costs, because of differences in the quantity and resources, that is, some countries have more minerals. In some countries, there is a lot of oil to some countries, forests, etc., with the differences in geography and climate. As a result, some items can be produced only in certain areas.