Explanation:

A tariff is a tax imposed by a government of a country or of a supranational union on imports or exports of goods. Besides being a source of revenue for the government, import duties can also be a form of regulation of foreign trade and policy that taxes foreign products to encourage or safeguard domestic industry. Tariffs are among the most widely used instruments of protectionism, along with import and export quotas.

Tariffs can be fixed (a constant sum per unit of imported goods or a percentage of the price) or variable (the amount varies according to the price). Taxing imports means people are less likely to buy them as they become more expensive. The intention is that they buy local products instead, boosting their country's economy. Tariffs therefore provide an incentive to develop production and replace imports with domestic products. Tariffs are meant to reduce pressure from foreign competition and reduce the trade deficit.