Money a commodity accepted by general consent as a medium of economic exchange. It is basically the legal tender of exchange. The paper currency which we use today has a long history behind it’s origin and evolution. Even today, money is continuously evolving, going from paper to plastic to digital. Over the years, money has changed it’s forms several times but what hasn’t changed is it’s functions. No matter what form it is used in, money almost always serves the same functions.
The functions of money are categorised as primary, secondary and contingent functions.

Primary Functions of Money:

Under this category, money performs it’s two main functions that are medium of exchange and unit of value. In the former case, money has removed the need of double coincidence of wants, something which was very much needed in the batter system which was used earlier. Being a medium of exchange means being generally acceptable. This gives the user freedom of choice and economic independence. It also acts as an intermediary and facilities exchange.
Money as unit of value means money is the standard for measuring values of all goods and services. This value is expressed in terms of price. Price is in terms of monetary unit and money acts as the determiner of rate of exchange. It also helps in calculating important economic parameters like costs, revenue, profits etc.

Secondary Functions of Money:

Under this, money performs three functions. It acts as a standard of deferred payments, it acts as a store of value and as a transfer of value. Money as a standard of deferred payments means that money acts as a standard for payments, which are to be made in future.
Money as a store of value means that money can be used to transfer purchasing power from present to future. Money is a way to store wealth. Although wealth can be stored in other forms also, but money is the most economical and convenient way. Money as a transfer value refers to the fact that money has velocity. It keeps transferring from person to other person.

https://www.yourarticlelibrary.com/economics/money/primary-and-secondary-functions-of-money/30307

Contingent Functions of Money:

Money performs certain contingent functions. These include: distribution of national income, maximization of satisfaction, basis of credit system, money as the most liquid asset. Money helps in distribution of the national product in the form of rent, wage, interest and profit, which are expressed in money terms. Money helps the consumers and producers in maximizing their satisfaction. A consumer derives maximum satisfaction when marginal utility is greater than marginal cost. Money helps in credit creation for banks. Money as a store of value has encouraged savings by people in the form of demand deposits in banks. These deposits are used for generating credit. Money is the most liquid asset of all assets in which wealth is healed. Individuals hold wealth in numerous forms ranging from currency, demand deposits, time deposits to bonds , savings, treasury bills etc. All these forms can be converted into money and vice versa.

https://www.yourarticlelibrary.com/economics/money/contingent-functions-of-money-in-economics/30310