Visa types granted by the United States of America are;
- United States of America Emergency Visa (on Holidays/Weekends)
- United States of America Visa for Diplomatic/official/ Laissez-Passers Passport Holder
- United States of America Visa for individuals working in designated US Agencies or technology areas
- United States of America Tourist Visa
- United States of America Business Visa
- United States of America Employment Visa
- United States of America Transit Visa
- United States of America Medical Visa
- United States of America Student Visa (Study/Research/Internship)
- United States of America Entry Visa
- United States of America Conference Visa
- United States of America Mountaineering Visa
- United States of America Missionary Visa
- United States of America Journalist Visa(Journalist/Documentary filming)
- United States of America Film Visa: Visa for shooting Feature Films
Here are some ESTA articles that might help you.