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.
Excise tax in the United States
Traditionally the federal government has left property taxes and sales taxes to the states and local governments for their revenue. Tariffs or customs duties on imported goods are essentially the only property taxes imposed by the U.S. federal government. Tariffs can be set only by the federal government, not by any state or local jurisdiction. For U.S. constitutional law purposes, a customs duty or tariff is nominally in a separate category from an excise tax. Excise taxes can be (and are) set by federal, state and local jurisdictions.