Money is a medium of exchange. It began when simple people held onto a good to exchange it later. Before this people needed to find somebody who wanted what they had and had what they wanted. This is called a double coincidence. Sometimes, people had to trade for things that they did not want just to trade it again for what they were after in the first place. Eventually, people started carrying around a product that they were not going to use, only to trade. Over time, precious metal coins became the currency. However, these coins were heavy, detectable, and easy to steal, so some people stored coins for others and gave them receipts in exchange. The receipts became so valued and trustworthy that most people stopped using coins in large quantities. Eventually, the governments and banks cut any ties to the precious metals and the slips of paper were just that. The only reason that paper money has any value is because people continue to pretend that it does.