Many people come to the United States to study here.
But many other people also come here to work, to visit relatives and to travel, to conduct business, and for many other reasons. For each reason there is a different type of visa. Someone who comes to the U.S. on vacation is considered a tourist and will have a B-2 visa. Someone who comes to the U.S. to conduct business, for example to have meetings with business partners here, would have a B-1 visa. Someone who has been sponsored for a company to work here in the U.S. for several years, usually has an H-1b visa.