The goal for this book is to give new employees in the payment business a fundamental understanding of how the payment business works from a technical perspective. I will take you on a journey from the very early days, before we invented money and all the way up to the invention of blockchain technology, which has made both Bitcoin, Ethereum, Solana, Algorand and other cryptocurrencies possible. I will walk you through all the different stakeholder in the current payment world. You will learn about Issuers, Acquirers, Card Brands, scheme networks, Payment-Service-Providers, and all other stakeholders in the payment business. Once you have finished this book, you should be able to identify all the different stakeholders, the stakeholders’ interests and what opportunities lie ahead for the different stakeholders in the payment business.