[A] The yen, the dollar, the quetzal, or the peso—no matter what the currency is called, money is an important part of life in nearly every culture today and has been throughout history. The concept of money dates back thousands of years. Originally, money was not metal coins or paper bills. Rather, people paid for things with objects that were useful and therefore considered valuable. We sometimes call this commodity money. Some examples of commodity money used throughout history are iron nails, rare seashells, bread, and livestock such as pigs or cattle.
[B] Salt and other spices were also used as money. In fact, the word salary (the money that employees are paid weekly or monthly by their employers) is derived from the Latin word salarium meaning a payment made in salt. The expression "He's (not) worth his salt" is probably derived from this because it was used to mean that someone's work was (or wasn't) worth the amount of money (salt) he or she was being paid. There is also evidence that, during the Middle Ages, pepper was used as a form of money, hence the old French saying "As dear as pepper." In England, one could actually pay one's rent in pepper! Even in more modern times commodity money has been used in cases where there was no access to actual currency. An example of this was during and after World War II in Europe, where tobacco was often used in place of money.
[C] Certain metals, such as gold, silver, and copper, have been used as commodity money for thousands of years. Metals were exchanged in the form of jewelry and nuggets and eventually appeared in the form of coins around 560 B.C.E. The use of metals coins as money became widespread after the use of the touchstone was discovered. A touchstone enabled people to find how much of a certain type of metal was contained in a lump and therefore determine its value. Eventually, the system of representative money emerged in the form of paper bills. This system is called