Numismatics is the study or collection of currency, including coins, tokens, paper money, medals and related  objects.

Alexander the Great memorial tetradrachm from the Temenos Mint c. 188–170 BC

The earliest forms of money used by people are categorized by collectors as "odd and curious", but the use of other goods in barter exchange is excluded, even were used as a circulating currency (e.g., cigarettes or instant noodles in prison). As an example, the Kyrgyz people used horses as the principal currency unit, and gave small change in lambskins; the lambskins may be suitable for numismatic study, but the horses are not. Many objects have been used for centuries, such as cowry shells, precious metals, cocoa beans, large stones, and gems.