Exports
An export in international trade is a good produced in one country that is sold into another country or a service provided in one country for a national or resident of another country. The seller of such goods or the service provider is an exporter; the foreign buyer is an importer. Services that figure in international trade include financial, accounting and other professional services, tourism, education as well as intellectual property rights.

Exportation of goods often requires the involvement of Customs authorities.

Trade Barriers
Trade barriers are laws, regulations, policy, or practices that protect domestically made products from foreign competition. While restrictive business practices sometimes have a similar effect, they are not usually regarded as trade barriers. The most common foreign trade barriers are government-imposed measures and policies that restrict, prevent, or impede the international exchange of goods and services.

Tariffs
Tariffs, a tax on a specific good or category of goods exported from or imported to a country, is an economic barrier to trade. A tariff increases the cost of imported or exported goods, and may be used when domestic producers are having difficulty competing with imports. Tariffs may also be used to protect an industry viewed as being of national security concern. Some industries receive protection that has a similar effect to subsidies; tariffs reduce the industry's incentives to produce goods quicker, cheaper, and more efficiently, becoming ever less competitive.