Money used to represent a medium of exchange that would facilitate bartering. Instead of exchanging goods or services, people would receive a piece of paper that was equal to the value of their goods or services. This was initially an honest system when for each service or goods offered there was only one bank note issued. Eventually the banker started to cheat and issued a lot more money/paper than the counter value produced in kind. And that was the beginning of money printing. It just became too tempting and convenient for governments and bankers to simply create more money since nobody would really know. So if the value of a day's work or a pig were both say $100, the money or paper issued for this should be $100 for each. But gradually governments/banks would issue more and more paper with nothing produced in return. All banks today lend at least 10x the money deposited so for every $100 received $1,000 is leant. But the leverage can be much greater like Deutsche Bank which is leveraged nearer 50x.