Overview
Generally, a citizen of a foreign country who wishes to enter the United States must first obtain a visa, either a nonimmigrant visa for temporary stay, or an immigrant visa for permanent residence. Visitor visas are nonimmigrant visas for persons who want to enter the United States temporarily for business (visa category B-1), tourism, pleasure or visiting (visa category B-2), or a combination of both purposes (B-1/B-2).
Here are some examples of activities permitted with a visitor visa: