Getting a U.S. visa starts with a question most applicants underestimate: which of the more than 20 nonimmigrant visa categories actually matches your specific purpose for traveling, since the entire application depends on getting that classification right from the start. * Visas split into two broad types. Immigrant visas are for people intending to live in the U.S. permanently — the visa path that eventually leads to a green card. Nonimmigrant visas cover everyone else: tourism, business, temporary work, and study, among many other purposes, each with its own specific visa letter-and-number designation, like the B-1 for business or B-2 for tourism. * The standard application process for most nonimmigrant visas runs through Form DS-160, completed online, followed by scheduling an in-person interview at a U.S. embassy or consulate, typically in your country of residence or nationality. At the interview, a consular officer evaluates your application and asks questions to determine whether you qualify for the visa category you're applying under, and digital fingerprints are usually collected the same day. * Not everyone needs a visa at all for short visits: citizens of countries participating in the Visa Waiver Program can travel to the U.S. for tourism or business for up to 90 days without one, though they still need to get approved through the Electronic System for Travel Authorization (ESTA) before departing. * One detail worth understanding clearly: a visa itself doesn't guarantee you'll actually be let into the country. It only authorizes you to travel to a U.S. port of entry — a Customs and Border Protection officer makes the final admission decision when you actually arrive.