Regardless of the purpose of travel to America, you should take care of obtaining a visa in the United States in advance. The application must be made at least three months before the planned date of the country visit. The process of obtaining a visa in the United States includes several stages, including the delivery of biometric data and an interview. Even the most ridiculous mistake, even if made by carelessness or ignorance, threatens to refuse.
Also, to open a visa, you must prove to the officer that your trip is not of an immigration nature and that you will leave the United States immediately after you finish your business.
There are various visa types:
Student Visa (F, M). This visa is one of the most popular visas and issued more often than others. It allows multiple visits to the United States, studying in various educational institutions.
Work Visa (H, L, O, P, Q, R). This visa is issued for professionals, workers who have been invited to the workplace and involves participation in obtaining both an employee and an employer.
Exchange Visitor Visa (J). This visa is issued to participants of cultural exchange programs, also to participants of the USA Summer Work and Travel program.
Transit / Crew Visa (C1 / D). This nonimmigrant visa requires the passage of a transit route through the United States, and is also issued to crew members on board a ship passing through the United States.
Journalist and Media Visa (I). This visa involves the entry into the United States to representatives of the media, journalists, reporters who are going to do their work.
Domestic Employee Visa (B1, A3, G5). This visa involves the entry into the US of workers such as butlers, cooks, drivers, and others who accompany their employer. The category of this visa depends on the visa of the employer.
More information about visas can be found on the US State Department website.