Currency is very diffrent from money. Most people eqaute them, but they are not the same. For instance currency is a dollar, or a pound. Money is a gold or silver coin. Its time for a list, that we need to remember the diferences about money and currency.
Medium of Exchange Yes Yes
Unit of Account Yes Yes
Portable Yes Yes
Durable Yes Yes
Divisible Yes Yes
Fungible( an be interchangable with others) Yes Yes
Store of Value No Yes
The biggest difference is a store of value. Some people call this its value, the amount in dollars, any adjective you want to use. What a store of value is, is the set amount of value in currency you could exchange this metal for. It will always have a value, it can never crash, it will never be worthless, and it has value no matter where you go. Its a long term advancemenet to invest in currency, metal, commdieties, inventions because they wont lose value. As the American dollar can crash, gold can never cash, it could lose value in dollars, but it can always be exchanged for something, and is a good metal. Silver is even better since, if needed, it can conduct electricity. A dollar bill can not do that. The value stored in a metal like gold or silver, is a much more solid investment compared to a dollar that has a changing value everyday.