A visa is an official endorsement placed within a passport that grants the holder permission to enter, leave, or stay in a country for a specified period. It does not guarantee entry into the country; instead, an immigration official at the port of entry determines the visa holder's eligibility for admission. The type of visa required is determined by the purpose of the traveler's intended visit and other facts, as per U.S. immigration law
. In the case of the United States, a citizen of a foreign country who seeks to enter the U.S. generally must first obtain a U.S. visa, which is placed in the traveler’s passport
. There are different types of visas, such as tourist, student, work, and transit visas, each with its own specific requirements and conditions
