Layer 1 is the commodity layer (Bitcoin)

Layer 2 is the collateral layer (Lightning)

Layer 3 is the credit layer (Cashu)

I know it’s uncool to refer to these as ‘layers’, but this exactly reflects the evolution of layered money since the Medici Family. The ‘standardized’ interface between the layers was the balance sheet, enabled by double entry accounting.

What is different today, is that the monetary technology is wildly different - the speed of settlement has caught up to the speed of transaction that scales globally and on the micro-level. And it’s all cryptographically enforced- no need for the Medici goons.

Figure credit: Nik Bhatia, Layered Money.