Tourism is travel for recreational, leisure or business purposes. The World Tourism Organization defines tourists as people who "travel to and stay in places outside their usual environment for more than twenty-four (24) hours and not more than one consecutive year for leisure, business and other purposes not related to the exercise of an activity remunerated from within the place visited". Tourism has become a popular global leisure activity. In 2007, there were over 903 million international tourist arrivals, with a growth of 6.6% as compared to 2006. International tourist receipts were USD 856 billion in 2007.

Despite the recent global recession, international tourist arrivals during the first four months of 2008 followed a similar growth trend than the same period in 2007. However, as a result of the economic crisis of 2008, international travel demand suffered a strong slowdown beginning in June 2008, with growth in international tourism arrivals worldwide falling to 2% during the boreal summer months, while growth from January to April 2008 had reached an average 5.7% compared to its 2007 level. Growth from 2006 to 2007 was only 3.7%, as total international tourism arrivals from January to August were 641 million tourists, up from 618 million in the same period in 2007.

Tourism is vital for many countries, such as the U.A.E, Egypt, Greece and Thailand, and many island nations, such as The Bahamas, Fiji, Maldives and the Seychelles, due to the large intake of money for businesses with their goods and services and the opportunity for employment in the service industries associated with tourism. These service industries include transportation services, such as airlines, cruise ships and taxis, hospitality services, such as accommodations, including hotels and resorts, and entertainment venues, such as amusement parks, casinos, shopping malls, various music venues and the theatre.