> I think they mean $20 worth of value be it gold or some other bankable theoretical material. Originally us dollars were tied to physical gold assets.
While dollars were originally tied to physical assets, I'm asking about what the central bank give me today for my 20 euros or dollars.
It doesn't matter. You get nothing directly, but that's not the point (and is part of the reason they got rid of the gold standard). The point is that the store will accept it as payment for an actual thing, and its employees will accept it as payment for actual work, and the stores they go to will accept it as payment for actual things, and their employees will accept it as payment for actual work, etc.
What you get is the stuff that you buy. Or more directly, what you get is buying power.
While dollars were originally tied to physical assets, I'm asking about what the central bank give me today for my 20 euros or dollars.