A visa is an endorsement on a passport and serves as proof of your compliance with the varying requirements of visitation to a particular country. A visa is not required for travel to every country, but if you do not have a visa to enter a country that requires you to have one, you will not be allowed to enter that country.
A visa establishes the reason for your need to be in a certain country, whether for tourism, business or immigration purposes. A visa usually expires in a set amount of time and needs to be renewed if you want to reenter or remain in the country. Government officials should be able to tell what type of visa you have, how long it is good for and whether or not multiple entries are permitted.
Specific visa restrictions may also be written in the visa or indicated by the class of visa. For example, people with tourist visas are generally not permitted to work. Immigration visas are generally issued to those seeking to gain citizenship in the country.
It can sometimes take months to obtain a visa. Anyone interested in visiting a foreign country should contact the consulate of the country he would like to visit as quickly as possible to determine if a visa is necessary.
