Tourism is travel for pleasure, and the commercial activity of providing and supporting such travel. UN Tourism defines tourism more generally, in terms which go "beyond the common perception of tourism as being limited to holiday activity only", as people "travelling to and staying in places outside their usual environment for not more than one consecutive year for leisure and not less than 24 hours, business and other purposes". Tourism can be domestic (within the traveller's own country) or international. International tourism has both incoming and outgoing implications on a country's balance of payments.
Between the second half of 2008 and the end of 2009, tourism numbers declined due to a severe economic slowdown (see Great Recession) and the outbreak of the 2009 H1N1 influenza virus. These numbers, however, recovered until the COVID-19 pandemic put an abrupt end to the growth. The United Nations World Tourism Organization has estimated that global international tourist arrivals might have decreased by 58% to 78% in 2020, leading to a potential loss of US$0.9–1.2 trillion in international tourism receipts.
