First of all, it is important to differentiate between the Immigrant Visa (IV) and Non-Immigrant Visa (NIV).

An Immigrant Visa (IV) is issued to a person wishing to live permanently in the United States.

A Non-Immigrant Visa (NIV) is issued to a person with permanent residence outside the United States, but wishes to travel to the United States on a temporary basis for tourism, medical treatment, business, temporary work or study. Foreign citizens who want to live permanently in the United States must first obtain an immigrant visa. This is the first step to become a legal permanent resident.