Immigration is the formal name for the procedure by which non-citizens enter the United States.
People come to America from all corners of the world.
Some come on vacation, to see the sights, to explore the country. Finally, there are people who come to the United States to obtain citizenship. They may enter on a residency permit, and eventually gain status as a permanent resident, and ultimately as a citizen. Each of these categories is discussed below. The INS is a unit of the United States Department of Justice.