Choosing a Visa: An Overview
This is an overview on what visa to choose from based on the purpose in traveling to the US. Generally, the US defines their visas into 2 categories (according to travel.state.gov):
Non-Immigrant Visas (you do not work towards US citizenship)
Immigrant Visas (you do work towards US citizenship)
Within these 2 categories, 4 types of visas based in the US include:
Tourist Visas (for traveling in the US)
Immigration & Naturalization Visas (including by marriage)
Student Visas (for studying in the US)
Work Visas (for working in the US)
Tourist Visas
Tourist visas are within the Non-Immigrant Visas category. The main purpose for tourist visas are for traveling, more or less, with some complexity depending on the exact purpose of travel. The US has reciprocal agreements with many countries while not having some with others.
Therefore, visitors traveling to the U.S. may need to consult apply, and be approved by the U.S. Department of State, which visa requirements differ per country. In order to obtain this visa, visitors must apply for ESTA (Electronic System for Travel Authorization) and be approved.
According to the ESTA website, there are currently 40 countries participating in the Visa Waiver Program (VWP). This program allows people from another country to visit the U.S. without a pre-authorized visa, which allows travel for up to 90 days without obtaining any other visa type. If you are not a citizen of these countries or were not approved in ESTA, you must apply for a B-2 tourist visa.
Immigration & Naturalization Visas
This visa type is within the Immigrant Visas category. The main purpose of this visa type is for allowing a person to permanently reside in the US as this towards the US naturalization/citizenship process. However, immigration does not necessarily suggest citizenship (ex: temporary refugee status).
For instance, a 'Green Card ' falls into this type of visa, which allows the holder to legally both live and work in the US. Although obtaining this visa is towards the path of obtaining US citizenship, it does not immediately grant US citizenship however. The Green Card holder must wait 5 years before applying for US citizenship as the final process, known as the citizenship/naturalization process.
Full rights to all laws (including being subject to them) are granted upon this process, which allows the holder to travel as a US citizen would. This is just one path/process under this type of visa. However, there are multiple paths/processes to obtaining this type of visa, such as through family, marriage, employment, refugee or asylum status, investments, diversity lottery, and "The Registry."
Student Visas
Student visas within the Non-Immigrant Visas category. The main purpose of student visas are for visiting the US for the purpose of an educational experience, such as attending classes and/or pursuing a particular educational degree (ex: bachelors, masters, PhD, etc.).
Student visas include foreign exchange students residing in the US for just a few weeks or a few years, depending on their education programs. Therefore, requirements may vary as per this visa type per country.
Any foreign national studying in the US will need a student visa, which falls under the sub-type letters F and M. Also sub-type letter J is included in this category, which are for academics and education professionals going abroad for particular work studies or trips to the US.
Work Visas
Work visas are within both Non-Immigrant and Immigrant Visas categories. The main purpose of a work visa is for authorization to work in the US. Since the US prioritizes jobs available to be filled by its own US citizens (preferably), work visas can be the most difficult to obtain out of all the visa types.
Many different work visas exist, which include sub-types (under letters):
Temporary Employment Visas: H, L, O, P, Q
Exchange Visitor Visa: J
Media Visa: I
Trade Treaty and Investor Visa: E
NAFTA Professional Worker Visa: TN/TD
If you have your own business (or in the process of starting), it may be easier to obtain a work visa. Interestingly of note, immigrants in the US are 80% more likely to start their own business than US native-born citizens themselves (according to an MIT study).