Visa
A visa is a stamp that a U.S. Embassy or consular office that is based in another country puts in a person’s passport. That stamp allows a person to enter into the United States as an immigrant or as a nonimmigrant. A person who is not a U.S. citizen but has a visa or a green card and who wishes to travel to a country outside of the United States must obtain a visa so the person can return to the United States.