A visa is a paper document affixed to a page of the holder's passport. It permits a person to travel to the State during the dates stated on the visa. It does not guarantee entry to the State. An Immigration Officer at the Port of Entry has the authority to grant or deny admission, and to decide on the duration a person may remain in the State.

A visa specifies certain reasons why that person will be staying in the country. It also specifies a certain time frame. Most of the time, visas are granted to people who work or plan to attend school in a nation for a select amount of time. It is really a supplement to the passport, since both are required at the same time. The visa is usually stapled or attached to the passport and shown at the time of entry into another country. Most visas have time limits, and typically that time extends to about six months. People can request that their visa be extended in certain circumstances, but there are usually strict requirements one must meet before getting a time extension. Just like passports, a travel insurance policy is recommended in case the paperwork is misplaced.