Visitor Visa - clarification required

[Bissa]

What is the difference between "I-134 Affidavit of Support" and "Sponsoring a visitor visa".

I often hear on this forum by number of people saying - "You can not sponsor your parent's visitor/tourist visa, let them apply on their own". When I say I sponsor - I meant providing I-134 form. Am I missing something here?

[pontevecchio]

I-134 is not mandated for getting a tourist visa. Tourist visas as per the USA cannot be sponsored as opposed to some developed countries where this is possible. If you want to pay for their trip, that is fine.