Are you asking about payments specifically or general "how things work" series?

When Apple Pay launched, Clover had a detailed post on tokenization. http://clover-developers.blogspot.com/2014/09/apple-pay.html

This three part comment of mine from an HN discussion several years ago covers similar material: https://news.ycombinator.com/item?id=2445866

a link in this thread https://github.com/alex/what-happens-when