Numismatics
Numismatics is the scientific study of money, including the history of its varied forms such as coins or bank notes.
While numismatics is often characterized as the collection of coins, it has more meaning and includes the much larger study of the means to pay for things and the exchange of goods.
In the past, cultures without money used the barter system to resolve debts. Prison societies use cigarettes as a form of currency. The Kyrgyz people used horses as currency and gave small change in lambskins.
See also