Comment by sanjeevverma1

this article doesn’t do a good job of simplifying. the vast majority of Visa’s revenue comes from one thing called the ISO 8601 / ISO 20022 message, which is the name for a Visa’s authorization. the core service is transmitting this message between an issuer (cardholder bank) and an acquirer (merchant bank). all other revenue streams are basically a microservice on top of this core message transmission service.