Tourism is travel for pleasure or business; also the theory and practice of touring, the business of attracting, accommodating, and entertaining tourists, and the business of operating tours. The World Tourism Organization defines tourism more generally, in terms which go "beyond the common perception of tourism as being limited to holiday activity only", 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.
Today, tourism is a major source of income for many countries, and affects the economy of both the source and host countries, in some cases being of vital importance. Tourism has become an important, even vital, source of income for many regions and even entire countries. The Manila Declaration on World Tourism of 1980 recognized its importance as "an activity essential to the life of nations because of its direct effects on the social, cultural, educational, and economic sectors of national societies and on their international relations."