There are two categories of U.S. visas: immigrant and nonimmigrant. Immigrant visas are issued to foreign nationals who intend to live permanently in the United States. Nonimmigrant visas are for foreign nationals wishing to enter the United States on a temporary basis – for tourism, medical treatment, business, temporary work, study, or other similar reasons.
An immigrant visa is issued to a foreign national who intends to live and work permanently in the United States. In most cases, a relative or employer sponsors the individual by filing an application with U.S. Citizenship and Immigration Services (USCIS). Certain applicants such as workers with extraordinary ability, investors, and certain special immigrants can petition on their own behalf. The application is later forwarded to the appropriate U.S. Consulate or Embassy overseas for continued processing and issuance of the immigrant visa to the intending immigrant, if eligible. An intending immigrant must present the immigrant visa at a U.S. port-of-entry prior to the expiration of the immigrant visa. An intending immigrant becomes a lawful permanent resident once the immigrant visa and accompanying paperwork is reviewed and endorsed by a CBP Officer.
Non-immigrant visas are issued to foreign nationals seeking to enter the United States on a temporary basis for tourism, business, medical treatment and certain types of temporary work. The type of nonimmigrant visa needed is defined by immigration law, and related to the purpose of the travel. Generally, an individual applies directly to the U.S. consulate or embassy abroad for a tourist (B-2) or business nonimmigrant (B-1) visa. However, foreign nationals seeking to enter the United States to study or work may require certain authorization and documentation prior to applying for a nonimmigrant visa.
Issuance of a visa does not guarantee entry to the United States. A visa simply indicates that a U.S. consular officer at an American embassy or consulate has reviewed the application and that officer has determined that the individual is eligible to enter the country for a specific purpose. The CBP Officer at the port-of-entry will conduct an inspection to determine if the individual is eligible for admission under U.S. immigration law.