It is much easier to obtain nonimmigrant visas, which are primarily issued to tourists and temporary business visitors. In 1993, the INS admitted 21,447,000 nonimmigrants to the United States. Nonimmigrant visas are divided into eighteen main categories ranging from vacationers and diplomatic personnel to athletes, temporary workers, and students. Most categories do not have any numerical limitation. The most significant issue in nonimmigrant visas is whether the alien may work in the United States without violating the terms of the visa.
Immigrants find visas much harder to obtain.
Millions of aliens want to live and work in the United States and enjoy the benefits of U.S. citizenship, but only a fraction of them can. Congress sets numerical limits on most types of immigrant visas, under the theory that the country can realistically absorb only so many new people. The 1995 annual ceiling was 675,000, with flexibility for some categories. In law, aliens granted visas are said to have obtained entry. An alien might cross the border, but still be determined by authorities not to have entered the country.