Adventure travel is a type of tourism, involving exploration or travel with a certain degree of risk, and which may require special skills and physical exertion. In the United States, adventure tourism has grown in recent decades as tourists seek out-of-the-ordinary or "roads less traveled" vacations, but lack of a clear operational definition has hampered measurement of market size and growth. According to the U.S.-based Adventure Travel Trade Association, adventure travel may be any tourist activity that includes physical activity, a cultural exchange, and connection with outdoor activities and nature.

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 or international, and international tourism has both incoming and outgoing implications on a country's balance of payments.