Non-Immigrant Visa Categories
B-1(business visitor)/B-2(tourist visitor) and ESTA (visa waiver): tourists and business visitors (cannot be used for employment)
F-1 (OPT): recently graduated students
J-1: visiting professors, researchers, and student interns
H-1B: professional, specialty occupations
TN: professional occupations; citizens of Mexico & Canada only
O-1: extraordinary ability in the sciences, arts, education, business, or athletics, or who has a demonstrated record of extraordinary achievement in the motion picture or television industry.