Ask HN: Where/How do I learn about credit card payments and payment gateways

I hope this is not the wrong place to post this.

I have been trying to learn about credit card payment gateways and I am not finding the proper resources. Specifically - * I read (on HN) sometime ago that there is a specific way the card numbers are issued by companies and that you could tell by the number which company issued it. Where do I get this information? * What exactly do the different players do in the ecosystem? We have the providers (Visa, MC), issuers (Citibank), payment gateways, processors. * When I swipe my card at Best Buy what happens after the card is read?

Could someone please point me in the right direction?