U.S. law provides for both immigrant and nonimmigrant visas. Immigrant visas (i.e., permanent resident status or green cards) allow for indefinite residence in the United States. Most immigrant visas are issued on the basis of family sponsorship or through employment (including investment).
In contrast, nonimmigrant visas allow entry only for a limited period an only to carry out specified activities. There are 24 major nonimmigrant visa categories, and 87 specific types of nonimmigrant visas issued. Each NIV category is identified by a particular letter, starting with “A” and currently using up the English alphabet through the letter “V.” The NIV application process is designed to be quicker and less cumbersome than that for immigrant visas.