Visas are official licenses that signal permission to enter or leave a country or region. In the United States, the primary type of visa is immigrant visas (also called permanent visas), which are offered to people who want to reside permanently. Nonimmigrant visas are also for visitors, allowing them to enter the U.S. for a specific purpose such as attending a conference, conducting research, or engaging in religious work.

Visa Law determines the procedures required to obtain a nonimmigrant visa, oversees various agencies, including the U.S. State Department (DOS), manages consulates and embassies worldwide, and determines which grounds of inadmissibility preclude individuals with certain types of characteristics or behaviors from entering the U.S. To obtain a nonimmigrant visa, an individual must visit a consulate or embassy.

There are a variety of classifications for individuals to visit the United States, all of which come with their benefits and requirements. Some of the most common include:
  • Students: Prepare for classes, gather research, attend a conference
  • Business visitors: Seek contracts in the U.S. or negotiate a deal.
  • Temporary and seasonal workers: Offer temporary labor or services in a profession they're familiar with (for example, a ski instructor)
  • Visitors for Pleasure and Vacation: Visit friends and family members, or explore the country independently
  • Temporary workers and trainees Are foreign employees assisting you regularly.
  • International representatives: Represent their company stateside.
  • Marriage Fiancs of U.S. citizens: Would like to marry U.S. citizens and live in the U.S.
  • Treaty Traders and Investors: Seek to expand your business abroad
  • Some visitors come to the United States for business or pleasure and do not need a visa, including citizens of the Visa Waiver Program (VWP) countries.

However, all VWP visitors must abide by the travel, business, and documentation requirements and return to their home country, residence, or country of citizenship. Visitors who meet these requirements will be issued a green I-94 card that cannot be extended, and they may not change their immigration status.

U.S. Visa Definition

More U.S. federal agencies are responsible for carrying out the immigration laws. Usually, part of the visa application process must be done in the country where the applicant resides, at a consulate or embassy managed by the Department of Homeland Security (DHS). For the nation's protection, people with specific histories will never be allowed a visa, green card, or entry into the U.S., even if they're in a close relative category. In immigration law terms, these histories are known as the grounds of inadmissibility.

For the United States for limited periods for various purposes. A nonimmigrant visa allows a foreign citizen to travel to the United States port-of-entry (generally an airport, seaport, or land border crossing) and request permission to enter the U.S. In exchange, the U.S. Department of State issues a visa to put the visitor in lawfully admitted status as a nonimmigrant.

Nonimmigrant visas are short-term, temporary visas for foreign nationals that allow them to enter the United States. They enable the visitor to enter the United States temporarily for specific purposes, which vary for each nonimmigrant visa type.

Because a visa is not necessary for short-term business visitors from one of the 38 countries in the Visa Waiver Program (VWP), the visitor must complete the Electronic System for Travel Authorization application and then apply for the travel authorization code (also known as ESTA). When the ESTA is approved, they will have up to 90 days to enter the U.S. for their business visit or vacation. They will also be given an authorization code on their ESTA. Once they arrive, they can enter the U.S. by presenting their ESTA documentation along with the approved I-94 card they received when entering the country.

The ESTA authorization code can only be used once, so the individual cannot enter the U.S. more than once with the same principle. For more details on travel to the United States under the Visa Waiver Program (VWP).