The type of visa you need is determined by the purpose of your intended travel and stay in the United States. The two main categories of visas to the U.S. are nonimmigrant and immigrant visas. Nonimmigrant visas are issued for the purpose of temporary travel to the U.S. Immigrant visas are issued to foreign nationals who intend to immigrate and remain in the U.S. permanently. There are more than 20 nonimmigrant visa types for people traveling to the United States temporarily. There are even more types of immigrant visas for those coming to live permanently in the United States. For an overview of visa types, please see Types of Visas for Temporary Visitors or Visa Types for Immigrants.