A visa is a permission granted by any country to enter that country. To secure a visa for any country, you must apply to the consulate office of that country in your own country. Visas granted by a foreign country may be of various types, with different conditions attached to each of them. A transit visa allows you to stay in that country just for a day or two, while a tourist visa may allow you to stay for periods up to several months. For a business visa, the frequency of the visa depends on your need to stay in that country. A student visa is granted to students and is generally valid for the period of study (including the grace period), and permission to work outside the university is not allowed.