What makes a coin a coin?

Coins are money, but money means more than just coins, a fact that we today are well aware of, thanks to the habitual use of paper money and credit cards. Coins are round pieces of metal at a value that is guaranteed by the state. Before the invention of coins in the 7th century BC, people paid with irregular pieces of metal or other precious materials, which were carefully weighed.

Even after coins became commonplace, other forms of money remained in circulation, including ingots, bills of exchange and increasingly, from the 19th century onward, paper money. Particularly in times of crisis people relied on all kinds of money such as clipped pieces of metal, called «klippe», while local authorities occasionally issued so-called emergency money. Today, commemorative coins and coin sets are struck especially for collectors; these, however, are usually not accepted in regular coin circulation.