Account

Unit of account

Main article: Unit of account

A unit of account is a standard numerical unit of measurement of the market value of goods, services, and other transactions. Also known as a "measure" or "standard" of relative worth and deferred payment, a unit of account is a necessary prerequisite for the formulation of commercial agreements that involve debt. To function as a 'unit of account', whatever is being used as money must be:

• Divisible into smaller units without loss of value; precious metals can be coined from bars, or melted down into bars again.
• Fungible: that is, one unit or piece must be perceived as equivalent to any other, which is why diamonds, works of art or real estateare not suitable as money.
• A specific weight, or measure, or size to be verifiably countable. For instance, coins are often milled with a reeded edge, so that any removal of material from the coin (lowering its commodity value) will be easy to detect.

Store of value

Main article: Store of value

To act as a store of value, a money must be able to be reliably saved, stored, and retrieved – and be predictably usable as a medium of exchange when it is retrieved. The value of the money must also remain stable over time. Some have argued that inflation, by reducing the value of money, diminishes the ability of the money to function as a store of value.