Hunziker and Krapf, in 1941, defined tourism as people who travel "the sum of the phenomena and relationships arising from the travel and stay of non-residents.
insofar as they do not lead to permanent residence and are not connected with any earning activity."In 1976, the Tourism Society of England's definition was: "Tourism is the temporary, short-term movement of people to destination outside the places where they normally live and work and their activities during the stay at each destination. It includes movements for all purposes." In 1981, the International Association of Scientific Experts in Tourism defined tourism in terms of particular activities selected by choice and undertaken outside the home.
The United Nations classified three forms of tourism in 1994, in its "Recommendations on Tourism Statistics: Domestic tourism", which involves residents of the given country traveling only within this country; Inbound tourism, involving non-residents traveling in the given country; and Outbound tourism, involving residents traveling in another country. The UN also derived different categories of tourism by combining the three basic forms of tourism: Internal tourism, which comprises domestic tourism and inbound tourism; National tourism, which comprises domestic tourism and outbound tourism; and International tourism, which consists of inbound tourism and outbound tourism. Intrabound tourism is a term coined by the Korea Tourism Organization and widely accepted in Korea. Intrabound tourism differs from domestic tourism in that the former encompasses policymaking and implementation of national tourism policies.
Recently, the tourism industry has shifted from the promotion of inbound tourism to the promotion of intrabound tourism, because many countries are experiencing tough competition for inbound tourists. Some national policymakers have shifted their priority to the promotion of intrabound tourism to contribute to the local economy. Examples of such campaigns include: "See America" in the United States; "Truly Asia" in Malaysia; "Get Going Canada" in Canada; "Peru. Live the Legend" in Peru; "Wow Philippines" in the Philippines; "Uniquely Singapore" in Singapore; "100% Pure New Zealand" in New Zealand; "Amazing Thailand" in Thailand; "Incredible India" in India; and "The Hidden Charm" in Vietnam.