eli5 How do governments track all currency (physical and digital) in order to always know the denominator (how much total money there is)?

Question

eli5 How do governments track all currency (physical and digital) in order to always know the denominator (how much total money there is)?

In: Economics

Answer 1

All currency is issued with a serial number for anti-counterfeiting purposes.

But really, governments *don’t* keep track of how much total money exists. They don’t need to – it wouldn’t serve a purpose.