The following are good articles to read about what money really is

The supply of money in an energy-scarce world 

2011. Richard Douthwaite.

Summary of this article:

Money has no value unless it can be exchanged for goods and services but these cannot be supplied without the use of some form of energy. Consequently, if less energy is available in future, the existing stock of money can either lose its value gradually through inflation or, if inflation is resisted, be drastically reduced by the collapse of the banking system that created it. Many over-indebted countries face this choice at present — they cannot preserve both their banking systems and their currency’s value. To prevent this conflict in future, money needs to be issued in new, non-debt ways.

Output in today’s economy gets a massive boost from the high level of energy use. If less and less energy is going to be available in future, the average amount each person will be able to produce will decline and real incomes will fall. These shrinking incomes will make debts progressively harder to repay, creating a reluctance both to lend and to borrow. For a few years into the energy decline, the money supply will contract as previous years’ debts are paid off more rapidly than new ones are taken on, destroying the money the old debts created when they were issued. This will make it increasingly difficult for businesses to trade and to pay employees. Firms will also have more problems paying taxes and servicing their debts. Bad debts and bankruptcies will abound and the money economy will break down.

Governments will try to head the breakdown off with the tool they used during the current credit crunch — producing money out of nothing by quantitative easing. So far, the QE money they have released, which could have been distributed debt-free, has been lent to the banks at very low interest rates in the hope that they will resume lending to the real economy.

Moreover, without equitable, locally and regionally controllable monetary alternatives to provide flexibility, the inevitable transition to a lower-energy economy will be extraordinarily painful for thousands of ordinary communities, and millions of ordinary people. Indeed, their transitions will almost certainly come about as a result of a chaotic collapse rather than a managed descent and the levels of energy use that they are able to sustain afterwards will be greatly reduced. Their output will therefore be low and may be insufficient to allow everyone to survive. A total reconstruction of our money-issuing and financing systems is therefore a sine qua non if we are to escape Vesuvius’ flames.