Tourism is travel for recreation, leisure, religious, family or business purposes, usually for a limited duration. Tourism is generally associated with international travel, but may also refer to travel to another place within the same country. The World Tourism Organization defines tourists as people "traveling to and staying in places outside their usual environment for not more than one consecutive year for leisure, business and other purposes". Tourism has become a popular global leisure activity. Tourism can be either domestic or international, and international tourism can be classified as either inbound or outbound tourism. Today, inbound tourism is a major source of income for many countries, especially in terms of foreign exchange earned by the country as a whole. It also has a substantial impact on the local economy and employment of a place frequently visited by tourists.