Tourism is an important, even vital, source of income for many countries. Its importance was recognized in the Manila Declaration on World Tourism of 1980 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."
Tourism brings in large amounts of income into a local economy in the form of payment for goods and services needed by tourists, accounting for 30% of the world's trade of services, and 6% of overall exports of goods and services. It also creates opportunities foremployment in the service sector of the economy associated with tourism.
The service industries which benefit from tourism include transportation services, such as airlines, cruise ships, and taxicabs; hospitality services, such as accommodations, including hotels and resorts; and entertainment venues, such as amusement parks, casinos,shopping malls, music venues, and theatres. This is in addition to goods bought by tourists, including souvenirs, clothing and other supplies.
source : wikipedia