A shipping container is a container with strength suitable to withstand shipment, storage, and handling. Shipping containers range from large reusable steel boxes used for intermodal shipments to the ubiquitous corrugated boxes. In the context of international shipping trade, "container" or "shipping container" is virtually synonymous with "(standard) intermodal freight container" (a container designed to be moved from one mode of transport to another without unloading and reloading).
The invention of shipping containers helped advance the globalization of commerce.
Free trade is a policy by which a government does not discriminate against imports or interfere with exports by applying tariffs (to imports) or subsidies (to exports) or quotas. According to the law of comparative advantage, the policy permits trading partners mutual gains from trade of goods and services.
Under a free trade policy, prices emerge from the equilibration of supply and demand, and are the sole determinant of resource allocation. 'Free' trade differs from other forms of trade policy where the allocation of goods and services among trading countries are determined by price strategies that may differ from those that would emerge under deregulation. These governed prices are the result of government intervention in the market through price adjustments or supply restrictions, including protectionist policies. Such government interventions can increase as well as decrease the cost of goods and services to both consumers and producers. Since the mid-20th century, nations have increasingly reduced tariff barriers and currency restrictions on international trade. Other barriers, however, that may be equally effective in hindering trade include import quotas, taxes, and diverse means of subsidizing domestic industries. Interventions include subsidies, taxes and tariffs, non-tariff barriers, such as regulatory legislation and import quotas, and even inter-government managed trade agreements such as the North American Free Trade Agreement (NAFTA) and Central America Free Trade Agreement (CAFTA) (contrary to their formal titles) and any governmental market intervention resulting in artificial prices.