A non immigrant visa is for international travelers, who are citizens of other countries and are coming to the United States on a temporary basis. This visa allows an individual to travel to a United States port of entry and request permission of the Department of Homeland Security to enter the United States. Though a non immigrant visa helps to get an individual access to the United States, it doesn't necessary guarantee it. An individual may use a non immigrant visa for a variety of temporary reasons including vacation, business, and medical treatment. The purpose, intent, and duration of the trip to the United States will need to be declared well in advance and be part of the application process to determine if an individual is granted a non immigrant visa.