With concerns like terrorism, overpopulation and economics, it is imperative for any nation to monitor who enters the country. A visa allows a central government to control how many foreign visitors can enter, how long they are allowed to stay and the activities they are allowed to participate in, such as tourism or work.
The visa application process allows a nation's consular and immigration departments to verify the identity of the traveler prior to his arrival. The traveler's criminal and economic backgrounds are usually investigated, as well as whether or not he carries any communicable diseases. If the consular department determines the traveler does not pass the stringent background test, it reserves the right to refuse entry before the traveler even lands on their soil.
When visiting another country for tourism or business, a traveler will be required to obtain a visa. Some nations do not require a visa for US citizens traveling under these circumstances. Other countries, such as Australia, will only require an Electronic Travel Authority (ETA) obtained through the airline, travel agent or Australian consular services.
If a U.S. citizen wishes to work in another country, permission to work is required. Granting a work visa to a foreign national will potentially take a job from one of its own citizens; therefore, there are strict rules regarding non-citizens desiring to work abroad. A visa allows the host country to determine if the applicant possesses unique skills not found among their own population.
A visa is important for the host country to determine who qualifies to permanently reside within their borders. It also allows a nation's immigration department to decide when a permanent resident can become a citizen, and when the foreign national first arrived is an important part of the citizenship process.
