What to read to understand central banking
I've found that the best starting point understanding money and banking is understanding that all money is very literally, nothing more, nothing less than debt. Your "money at bank account"? Very fundamentally, nothing but a credible statement from the bank that they owe you the amount of money.  Obviously, you do not need to have any assets in the first place to make the statement. To make it credible is a bit more difficult trick.