Tariff
A tariff is a tax on imports or exports between sovereign states. It is a form of regulation of foreign trade. It is a policy that taxes foreign products to encourage or protect domestic industry. It helps limit trade deficits. The tariff is historically used to protect infant industries and to allow import substitution industrialization.
Non-tariff barriers to trade
Non-tariff barriers to trade (NTBs) or sometimes called "Non-Tariff Measures (NTMs)" are trade barriers that restrict imports or exports of goods or services through mechanisms other than the simple imposition of tariffs. The Southern African Development Community (SADC) defines a non-tariff barrier as ""any obstacle to international trade that is not an import or export duty. They may take the form of import quotas, subsidies, customs delays, technical barriers, or other systems preventing or impeding trade."" According to the World Trade Organization, non-tariff barriers to trade include import licensing, rules for valuation of goods at customs, pre-shipment inspections, rules of origin ('made in'), and trade prepared investment measures.