The U.S. provides temporary visas to persons who, for a variety of reasons, do not intend to make the U.S. their permanent home. Such persons include students, trainees, persons who are on a temporary assignment for an employer in the U.S. professionals, labor workers, entrepreneurs, investors, and other persons who wish to work or remain in the U.S. for a limited period of time.
Foreign nationals who are residing in the U.S. for a temporary period of time are referred to as non-immigrants. Unlike immigrant visas, most non-immigrant visas are not limited to a numerical restriction – that is, with most non-immigrant visas there is no cap on the number of visas that will be awarded each year.
Also, certain non-immigrant visas allow foreign nationals to work in the U.S. while their green card application is pending.