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.
Protective tariff
Protective tariffs are tariffs that are enacted with the aim of protecting a domestic industry. They aim to make imported goods cost more than equivalent goods produced domestically, thereby causing sales of domestically produced goods to rise; supporting local industry. Tariffs are also imposed in order to raise government revenue, or to reduce an undesirable activity (sin tax). Although a tariff can simultaneously protect domestic industry and earn government revenue, the goals of protection and revenue maximization suggest different tariff rates, entailing a tradeoff between the two aims.