A visa is issued by a U.S. Embassy or Consulate.  A visa entitles the holder to travel to the United States and apply for admission; it does not guarantee entry.  An immigration official at the port of entry determines the visa holder’s eligibility for admission into the United States.

The purpose of your intended travel and other facts will determine what type of visa is required under U.S. immigration law. As a visa applicant, you will need to establish that you meet all requirements to receive the category of visa for which you are applying.