Travel is to move from one place to another in a short trip or a long distance or duration in any number of the following reasons :

Frequenting Works
Tourism
Trade or business
Visit relatives
Migration from one country to another .
Hajj , a traveling religious worship .
Treatment.
Inadvertently exploration and scientific research and investigation and information gathering .
Study Abroad ( application of science or scholarship ) .
Recognition of other cultures ( cultural exchange ) .
Recreation , relaxation and recuperation .
Attend the official events .
Diplomacy.