Tourism involves the movement of people. That movement might either be within their own countries - which is called “domestic tourism” - or to and from other countries - which is called “international tourism”.
In either case, the movement of people involves travel, by different means (by road, or by rail or by water or by air, or by a combination of two or more of these ‘modes of transport’, as they are called) over long or short distances. Therefore, tourism and travel are completely interrelated.
1976 - by the forerunner of The Tourism Society (The Institute of Tourism in Britain):-
“Tourism is the temporary short-term movement of people to destinations outside the places where they normally live and work, and activities during their stay at those destinations; it includes movement for all purposes, as well as day visits and excursions.”
1981 - by the International Conference on Leisure-Recreation-Tourism:-
“Tourism might be defined in terms of particular activities selected by choice and undertaken outside the home environment. Tourism might or might not involve overnight stays away from home.”
The following - a third - definition of tourism was devised by the then World Tourism Organization (WTO) and was endorsed by the Statistical Commission of the United Nations in 1993, following an International Government Conference in Canada in 1993:-
“Tourism comprises the activities of persons travelling to and staying in places outside their usual environment for not more than one consecutive year for leisure, business or other purposes.”