Travel is movement of people between relatively distant geographical locations for any purpose and any duration, with or without any means of transport. Travel also includes relatively short stays between successive movements. Movements between locations requiring only a few minutes are not considered as travel. The term "travel" originates from the Middle English word travail. The term also covers all the activities performed during a travel (movement). A person who travels is called a traveler in the United States, and traveller in the United Kingdom. Purpose of travel include recreation or tourism, research travel for the gathering of information, for holiday to visit people, volunteer travel for charity or, migration to begin life somewhere else, religious pilgrimages and mission trips, for business trade or commuting, and other reasons, such as to obtain health care or fleeing war. Travel may occur by human-powered transport such as walking or bicycling, or with vehicles, such as public transport, automobiles, trains and airplanes. Motives to travel include relaxation, discovery and exploration, interpersonal relationships and getting to know other cultures. Travel may be local, regional, national (domestic) or international. In some countries, non-local internal travel may require an internal passport, while international travel typically requires a passport and visa. A trip may also be part of a round trip, which is a particular type of travel whereby a person moves from their usual residence to one or several locations and returns.