If you’re a citizen of a foreign country, in most cases you’ll need a visa to enter the United States. A visa is a temporary permit that allows you to travel to the United States as far as the port of entry (airport or land border crossing) and ask the immigration officer to allow you to enter the country. Only the immigration officer has the authority to permit you to enter the United States. He or she decides how long you can stay for any particular visit. Visits are usually for reasons of employment, but may also extend to travel and leisure.
There are two categories of U.S. Visas: Immigrant and Non-immigrant:
1. Immigrant visas are for people who intend to live permanently in the U.S.
2. They also offer forms for U.S. citizens wishing to apply for non-immigrant visa for their overseas fiancé or spouse. The K Visa process is a newer, faster way of entering the United States. It offers individuals alternatives to going through the whole immigrant visa application process while overseas.