All things being equal, and in the long run, the price level is proportional to the money supply. Money is a medium of exchange and usually serves as a store of value for individual agents. It is intrinsically nominal. What matters is not money, but what you can buy with it. In fact, most money exists only in cyberspace - in bank deposits.
Money is a gigantic con trick - but an enormously useful one.
It may be the greatest technical advance of all time. The key financial player is the Bank. The Bank Supplies cash to the monetary system. Banker to the Government and to the banks. Operates foreign exchange reserves.