A Transit visa is a visa category issued for applicants traveling thru another country which is not the final destination just for transiting the country, (for e.g.,: If you are traveling to Trinidad and Tobago (T and T) from India there are no direct flight, so you will be traveling via Europe or US for which you will need a visa if there is requirement for you to change your flight and if you need to come out of the transit area) transit visa are issued for a specific duration.