A tariff is a tax on goods levied at the time of importation. Most tariffs are imposed at the national level though regional tariffs are possible. Tariffs come in a variety of flavors, and the amount charged can be based upon the value of the item or upon some other method-perhaps by weight or volume. The proceeds of most tariffs are enjoyed by the government.
Tariffs are assessed for a variety of reasons-most political in nature. They may be intended to raise the price of foreign goods to allow for better domestic competition or they may be intended to make an imported item so expensive that nobody chooses to afford it. In modern commerce, tariffs are complex and often sources of international dispute.