A customs union is a free trade area in which all members shares the same tariffs and quotas when importing from non members.

The factors of production are used the production of goods and services. There are four factors of production: Land, Labor, Capital Goods, Entrepreneurship.

A free trade area (FTA) is a type of trade bloc in which members have signed a free trade agreement.

A preferential trade area (PTA) is a type of trade bloc in which tariffs have been reduced, but not completely removed, between members.

A trade bloc is a group of countries in which trade is made easier between members by removing or reducing tariffs and other barriers to trade.