how do I Invite a friend from India to attend wedding in USA?

Details:

My status - I’m a US citizen,

  1. How do I Invite a friend from India to attend wedding in USA?

  2. Is there a difference between Visitor visa and tourism visa?

  3. Do we need to follow visitor visa process?

  1. They need to apply for B-1/2 visa

  2. No

  3. Yes, visitor visa or tourist visa process - both are same.