Throughout history, many different objects have been used to facilitate trade for goods and to measure wealth. Today, we usually think of dollars and coins when we define what we regard as money, although much commerce is carried out without any physical currency at all. Value is counted by entries in bank and credit card accounts, and the transfer of money often takes place through electronic impulses between computers. Objects have served the same purposes as well, in other times and places.

Throughout Africa's past, many objects have served as money—salt, shells, beads, metal, indigenous coins, European coins, jewelry, woven cloth, weapons and tools. The keys to understanding why a particular object came to be used as currency are acceptability and value. Acceptability encompasses such aspects as familiarity, usefulness and artistic expression, which add to the intrinsic value of the medium itself. Thus, while the scarcity of copper might have caused it to be exchanged on that basis alone, its use was further validated through the forms into which it was cast. Iron was more ubiquitous in African societies, but refining, forging, forming and decorating similarly increased its value.