AMEinfo published an article from on how your card works.

There are series of steps that take place from the moment you swipe your card until your payment gets processed and the transaction is completed. Not only are these invisible to the naked eye but also take place in a matter of seconds. Along with the cardholder and the merchant, there are a number of other key players involved as the transaction goes through. These are the merchant’s bank (acquiring bank), cardholder’s bank (issuing bank) and the card network (Visa, MasterCard, Amex).

For full article go to AMEinfo.