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.
Import Surtaxes
Import surtaxes, also known as special tariffs, are extra taxes on top of the normal import tax of imported goods, with the extra taxes being reserved for some purposes. They are different from import duty, which is not reflected in the customs tariff and is set for a specific purpose. Often, they depend on their level of taxation, which is the specific purpose for their collection. They are usually temporary or one-off.