This document discusses trade barriers and their objectives and types. It notes that trade barriers can be tariff barriers like taxes or duties on imports, or non-tariff barriers like quotas, licenses, and sanctions. The objectives of trade barriers are to protect domestic industries, promote development, maintain a favorable balance of payments, and generate government revenue. The key types of tariff barriers are import duties, export duties, specific duties, and preferential tariffs under single, double, or triple column tariff systems. Non-tariff barriers include quotas, embargoes, licenses, and sanctions.