A business visa can be used for a number of reasons. However, one of the big components of this type of visa is that it is for a specific, business-related event, not ongoing work. This type of visa can be used by an athlete coming into town for a tournament, a business seeking an investor, an employee attending a specific conference, a researcher completing research, a lecturer attending a trade show or conference, or someone training for a very brief period of time. Another huge component to this visa is that you are not paid by a US-based company other than expenses related to the event, such as prize money for an athlete or hotel and food-related expenses.