Since the end of World War II, the dollar has been the underpinning of the world’s economy. It is commonly referred to as the world’s reserve currency.
Money
As noted in Money, Money, Money, Money, the banking system evolved as the logical way to store money safely and allow people to transact business across distances. Initially, banks simply stored money for a fee and helped people pay for goods and services. But soon they also began to loan some of that money out.
Since the beginning of their existence on earth, humans have needed ways to trade with each other. Initially, there were simple barter systems. One person had wheat and someone else had milk, so they could swap wheat for milk, and both of them end up with both wheat and milk. That simple example didn’t actually go very far. If the person who had milk didn’t want wheat, there was no way for them to do a deal.