Currencies in most countries have very little physical value but a psychological monetary value the citizens trust making the concept of money very peculiar. Different countries each use different currencies as a way for people to exchange services, and every system is consistent. Trading services would be much more difficult without the use of a currency because people would have to seek out an individual who has what they want. The biggest problem is that the likelihood of this is very small and chance is that the value of the exchanged services are different. For example, if I am very good at making muffins and I want to purchase bread, I could trade 2 or 3 muffins for a single loaf. Though if I wanted to trade for a car, I would have to sell the company thousands of muffins let alone the fact that the company may not even want muffins. Currency bridges this gap by turning services into a steady valued universal object that can be trusted and understood by everyone in a society.
The people of Yap utilized carved limestone, or fei, as their currency because producing and bringing it back to the island took a great deal of work which gave it value. Much like the dollar, fei represented a psychological value beyond its physical worth that gave everyone on the island trust that they would later be able to trade it for services. The system the people of Yap had created for themselves is just as rational as the system we use in the United States. The people of Yap trusted the system so much that they would trade the ownership of fei without actually physically transferring the stone. Imagine being offered the ownership of a stone that was located in the bottom of the ocean. If everyone else in the area accepts it for deeds in return then it works just fine as currency. Similarly, in the United States, a majority of people use credit cards adding and subtracting digital numbers representing the amount of physically money they would own. Just like the people of Yap, the physical-less system allows people to easily purchase services and goods without having to provide one back. This agreed system also allows people to exchange services without having to search for someone specific who wants a service they may or may not be able to provide back.
Currency instills trust in its owners as long as it can be traded for a service. The system we use in the United States does just that by being accepted at every story and by every person. What money represents varies from person to person. Some people may view a dollar as a coffee while others view it as the hard work they put out to earn it. Not only does it change in representation but it also oddly changes in value; where the rich may leave a dollar laying in the street, the poor will grab, seeing it with much more value. Having a currency connects the society to a consistent system of trading services back and forth with littler hassle. A society’s belief and trust in a currency system, knowing that tomorrow it will be equally accepted, causes it to be successful.