Who is Visa?

[Bonzo 2000]

While the banks issue our credit cards and the money to finance them, who (or what) is VISA?

[willow74]

Visa is an association of 21,000 banks and other financial organisations worldwide. These Visa members are card issuers who set fees and interest rates.

Visa itself set the global standards that allow you to use your card everywhere
Investigate new technologies and opportunities that will bring you even more convenience and choice
Create new ways to pay that suit different groups of people - and different ways of life
Run the telecommunications and computer network that links every Visa member, every retailer that accepts Visa payments and more than 800,000 cash machines worldwide

[stevie21]

they even have a website catchily titled
http://www.visa.com