B-1/B-2: the visitor visa for business and tourism
The B visa is how most visitors enter the United States: the B-1 for business that is not employment (meetings, conferences, negotiating contracts, training, investigating an investment), the B-2 for tourism, visiting family, medical treatment and social events. Citizens of more than 40 countries can skip it under the Visa Waiver Program: an ESTA authorisation and up to 90 days per visit. Everyone else applies at a consulate on Form DS-160, pays the fee and attends an interview, where the law presumes the applicant intends to immigrate until they show ties that will bring them home. A B visa is usually valid for years and many entries; each entry is admitted for a set period, typically 6 months, shown on the I-94. Overstaying it, working on it, or using it to move here permanently are the three ways it goes wrong.
Education, not legal advice.
Talk to an attorney who does B-1/B-2 work