Temporary or non-immigrant visas provide for temporary travel to the U.S. Each temporary visa category allows for different activities and has different requirements.
B-1 visas allow for business activities but do not permit work. B-2 visas are for tourists. F-1 student visas allow for U.S. studies and, through Curricular Practical Training (CPT) and Optional Practical Training (OPT) programs, they allow for short term work authorization.
Others are available to foreign nationals from any country, provided there is a U.S. employer willing to serve as a petitioner and that the foreign national and the offered job meet specific requirements. These visa categories include the H-1B for workers in specialty occupations, the L-1 for intracompany transferees, the O-1 for individuals with extraordinary abilities, the P-1 for athletes and entertainers, the J-1 for interns, and the R-1 for religious workers.