B1 visa:


consult with business associates
attend a scientific, educational, professional, or business convention or conference
settle an estate
negotiate a contract

B2 visa:


tourism
vacation (holiday)
visit with friends or relatives
medical treatment
participation in social events hosted by fraternal, social, or service organizations
participation by amateurs in musical, sports, or similar events or contests, if not being paid for participating
enrollment in a short recreational course of study, not for credit toward a degree (for example, a two-day cooking class while on vacation)

materials needed:

[url=https://travel.state.gov/content/visas/en/visit/visitor.html]https://travel.state.gov/content/visas/en/visit/visitor.html[/url]