What are the differences between Single, Double, Multiple entry visas?
Visas can be single-entry, which means the visa is cancelled as soon as the holder leaves the country, double-entry, or multiple-entry, permitting double/multiple entries into the country with the same visa. Countries may also issue re-entry permits that allow temporarily leaving the country without invalidating the visa. Even a business visa will normally not allow the holder to work in the host country without an additional work permit. Once issued, a visa will typically have to be used within a certain period of time, and the period of validity starts only on entry into the country.