Unit of accountMain article: Unit of account
A unit of account (in economics[25]) is a standard numerical monetary 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 estate are 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 valueMain 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.[4]

Standard of deferred paymentMain article: Standard of deferred payment
While standard of deferred payment is distinguished by some texts,[5] particularly older ones, other texts subsume this under other functions.[4][22][23] A "standard of deferred payment" is an accepted way to settle a debt – a unit in which debts are denominated, and the status of money as legal tender, in those jurisdictions which have this concept, states that it may function for the discharge of debts. When debts are