Nonimmigrant visas are for temporary visitors to the United States such as for tourism, business, work, and studying.
Temporary workers (H and L Visas) can work in the U.S. after a petition is submitted by the employer-to-be in the United States and is approved by the USCIS. H1B Visas (for Specialty Occupations) is given to college-educated professionals (e.g. software programmers).
In this status, they can work for a total of six years in the United States. H1C Visas are for Registered Nurses, H2B for Non-Agricultural Workers, and H-3 for Trainees. The L Visa is for Intra-Company Transferees who are executives or managers of foreign-based companies or who are essential, specialized-knowledge employees. Nonimmigrants apply to come to the U.S. on a temporary basis on either a B-1 Visa for business (e.g. attending conferences, business meetings) or on a B-2 Visa for pleasure (e.g. tourism, visiting friends or relatives).
These visas require that the applicant has permanent residence in the home country, which s/he has no intention of abandoning, that the person enters the U.S. for a temporary period, and that s/he engages in activity relating to business or pleasure (no employment).
The U.S. attracts many foreign nationals to its diverse and strong institutions of learning. The F-1 Visa (Academic Student) allows one to enter the U.S. as a full-time student at an accredited (U.S. government- approved) college or university. The student must be enrolled in a program or course of study that culminates in a degree, diploma, or certificate. The M-1 Visa (Vocational Student) is issued to students who want to pursue non-academic programs (health care technician, machinist, dental hygienist, etc) in an established institution. The J-1 Visa (Exchange Student) is for students pursuing graduate / post-graduate studies, visiting scholars, medical doctors undergoing training, etc.
In order to obtain a K-1 fiancé(e) visa, you and your fiancé(e) must intend to marry each other within 90 days of your fiancé(e) entering the U.S as a K-1 nonimmigrant. Your marriage must be valid, meaning both you and your fiancé(e) have a bona fide intent to establish a life together and the marriage is not for the sole purpose of obtaining an immigration benefit.
An S nonimmigrant is an individual who has assisted a law enforcement agency as a witness or informant. A law enforcement agency may submit an application for permanent residence (a green card) on behalf of a witness or informant when the individual has completed the terms and conditions of his or her S classification.