These questions are about the requirements for a foreign national to obtain legal permission to enter the United States for any purpose.
The visa policy of the United States deals with the requirements which a foreign national wishing to enter the United States must meet to obtain a visa, which is a permit to travel to, enter, and remain in the United States. Visitors to the United States must obtain a visa from one of the United States diplomatic missions unless they come from one of the visa-exempt countries or Visa Waiver Program countries. The same rules apply to Puerto Rico and the United States Virgin Islands while different rules apply to Guam, Northern Mariana Islands and American Samoa.
