What Is Money? Definition, History, Types, and How It Is Created

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Money is anything that a society generally accepts as payment for goods, services and debts. In economics, it is defined by what it does: it works as a medium of exchange, a unit of account and a store of value. Coins, paper notes and the balances in bank accounts all count as money because people accept them in trade and price things in them. Gold, beaver pelts and tobacco have also served that role at different times. What gives something monetary value is shared acceptance, backed either by the usefulness of a physical commodity or by trust in the government and economy that issue it.

What Money Means in Economics

The meaning of money in economics is narrower than its everyday sense. In conversation, “money” often means wealth (“she has a lot of money”) or income (“he makes good money”). In economics, money is the specific set of assets people use to settle transactions. A house can be worth $400,000, but you cannot hand a slice of it to a grocer. The house is wealth. The balance in a checking account is money.

The three functions explain what money is for:

1. Medium of exchange. Money is accepted in trade by people who do not plan to consume it. A baker accepts dollars for bread because the baker knows a landlord, supplier or employee will accept those same dollars. This removes the need to find a trading partner who wants exactly what you have.
2. Unit of account. Money is the common measuring stick for prices, wages, debts and profits. Because everything is quoted in dollars, a buyer can compare a $3 coffee, a $30 book and a $30,000 car directly, and a business can add up revenues and costs in one unit.
3. Store of value. Money can be held today and spent later. It is not a perfect store, since inflation erodes it over time, but it holds value well enough over short periods that people can receive income on Friday and spend it next month.

Many textbooks add a fourth function, standard of deferred payment: loans, leases and wage contracts are written in money terms, which lets people agree today on payments that will be made years from now.

An asset can perform some functions and not others. A savings bond stores value but is not accepted at a checkout. During periods of very high inflation, people sometimes keep pricing goods in local currency while saving in a foreign currency or in goods, which splits the functions between two assets.

How Money Solves the Barter Problem

In a pure barter economy, two people trade only if each has something the other wants, a condition economists call the double coincidence of wants.

Suppose a farmer has cows and wants bananas. The farmer must find a banana grower who also wants beef. If the only interested person has potatoes, the farmer must then find someone with bananas who wants potatoes, and the chain grows with every trade. Barter also struggles with divisibility: a whole cow is worth far more than a bunch of bananas, and a live cow cannot be split without destroying its value. The two sides would need a separate exchange rate for every pair of goods.

Money fixes both problems. The farmer sells the cow to whoever wants beef, receives money in a divisible form and spends part of it on bananas, keeping the rest for later.

The Barter Myth

The cow-and-bananas story is a teaching model, not a historical record. Anthropologists have found no society that ran on pure barter before money appeared; small communities seem to have relied on informal credit, gift exchange and obligations tracked over time. Recorded barter usually appears where people already knew money and it had become scarce, as in the American colonies described below.

Types of Money

Money comes in several forms, classified by what gives it value.

Commodity Money

Commodity money is a good that also functions as currency. Its value comes, at least partly, from the good itself. In the 17th and early 18th centuries, American colonists used beaver pelts and dried corn in trade. Other societies used salt, cattle, shells and metals.

Goods that served well as money shared certain traits. They were widely wanted, so people accepted them readily. They were durable enough not to rot, portable enough to carry and easy to store. Ideally, they were also divisible and uniform, so one unit could be counted as equal to another.

Precious metals, especially gold and silver, are the most advanced form of commodity money. Unlike pelts or corn, gold has limited practical use for most people: you cannot eat it, and it will not keep you warm. It is valued largely because people find it beautiful and know that others do too, which shows that money’s value rests on what people collectively believe it can buy.

Representative Money

Representative money is a paper note or other token that can be redeemed for a fixed amount of a commodity. Under a gold standard, a paper dollar was a claim on a stated quantity of gold. People traded the paper because it was lighter and easier to handle than metal, while the redemption promise anchored its value.

Fiat Money

Fiat money is not backed by a physical commodity and cannot be redeemed for one. Its value comes from government decree, from its status as legal tender for debts and taxes, and from people’s confidence that it will keep buying things. The U.S. dollar, the euro, the Japanese yen and almost every other national currency today are fiat money.

Fiat money developed partly because gold is scarce. A growing economy needs more money to support more transactions, and it cannot always mine or acquire enough gold to back that money. Tying money to gold also limits a government’s ability to respond to recessions or banking panics.

In 1971, the United States ended the ability of foreign governments to convert dollars into gold, and the change was made official in 1976. From then on, the dollar was no longer redeemable in gold and its price was no longer fixed to gold. Only the strength of the U.S. economy, and confidence in its institutions, backs the dollar’s value.

Commercial Bank Money and Digital Money

Most money people use is neither coins nor notes. It is deposits: the balances recorded in checking and savings accounts at commercial banks. When you pay with a debit card, a bank transfer or a payment app, you are moving deposit balances, not physical currency. Tools such as a digital wallet change how payments are made, but the money underneath is usually still a bank deposit or a card-linked account.

What Gives Fiat Money Its Value

If a dollar bill cannot be exchanged for gold, why does anyone accept it? Several reinforcing reasons hold the system together:

• Legal tender and taxes. The government accepts its own currency for tax payments and declares it valid for settling debts. Everyone who owes taxes needs that currency.
• Network acceptance. People accept dollars because other people accept dollars. Each acceptance makes the next one more likely.
• Economic output. Money is only worth what it can buy. A productive economy that keeps supplying goods and services people want gives its money real purchasing power. The stronger the economy, the more its currency tends to be sought after, and the reverse is also true.
• Institutional credibility. Confidence that the central bank will not issue money recklessly keeps people willing to hold the currency.

If an economy weakens badly, its currency loses value in two ways: at home through inflation (each unit buys less) and abroad through a falling exchange rate (each unit buys less foreign currency). This is why printing new money does not by itself create wealth. More money chasing the same amount of goods raises prices rather than output.

Worked Example: Purchasing Power Over Time

The value of fiat money is its purchasing power, and inflation reduces it. The real value of a sum after a number of years can be estimated with:

Real value = Nominal amount ÷ (1 + inflation rate)^years

Hypothetical example: you keep $1,000 in cash for 10 years, and inflation averages 3% per year (an assumption chosen for illustration, not a forecast).

• 1.03^10 ≈ 1.3439
• $1,000 ÷ 1.3439 ≈ $744

The bills still say $1,000, but they buy roughly what $744 bought at the start. The calculation assumes a constant rate; actual U.S. inflation varies and is measured by the Consumer Price Index. Holding large cash balances also has an opportunity cost in the return that money could have earned elsewhere.

Measuring Money: M1, M2 and M3

Economists and investors track the money supply to judge inflation pressure, spending and credit conditions. Because assets are “money-like” to different degrees, the supply is measured in layers, from the narrowest and most spendable to the broadest.

• M1 covers money that can be spent immediately: currency in circulation (coins and paper money held by the public), demand deposits such as checking accounts, and other liquid deposits. In the United States, the Federal Reserve reclassified savings deposits as part of M1 in 2020, since they had become nearly as easy to spend as checking balances. Travelers’ checks have historically been included as well.
• M2 includes everything in M1 plus “near money”: small-denomination time deposits such as certificates of deposit, and balances in retail money market funds. These can be turned into spendable money fairly easily, but not always instantly or without some cost.
• M3 is the broadest traditional measure. It adds large time deposits, institutional money market funds, short-term repurchase agreements and other large liquid assets. The Federal Reserve stopped publishing M3 in 2006, judging that it added little beyond M2, though some other central banks still track a comparable broad measure.

The definitions differ from country to country, so an M2 figure for one economy is not directly comparable with another country’s M2.

How Money Is Created

Two kinds of institutions create money in a modern economy: the central bank and commercial banks.

Central Bank Money

A central bank such as the Federal Reserve creates base money: the physical currency in circulation plus the reserve balances commercial banks hold at the central bank. Physical bills are only a small share of the total money supply.

The central bank’s main tools to influence money and credit are:

• Open market purchases. When the central bank buys government bonds or other fixed-income securities, it pays by crediting the seller’s bank with new reserves. The central bank does not need to have the money first; it creates the money when it makes the purchase. Large-scale versions of these purchases are called quantitative easing.
• Open market sales. To shrink the money supply, often to fight inflation, the central bank sells securities. The money buyers pay is effectively withdrawn from circulation.
• Interest rates. By lowering its policy rate, the central bank makes it cheaper for banks to borrow and lend. Low-cost credit, sometimes called cheap money, encourages businesses and households to borrow and spend. Raising rates has the opposite effect. In the United States, the key target is the federal funds rate.

Commercial Bank Money

Most of the money people spend is created by ordinary banks when they lend. A bank does not lend out a stack of other customers’ savings. When it approves a loan, it credits the borrower’s account with a new deposit, and that deposit is new money.

Hypothetical example: a bank approves a $20,000 car loan.

1. The bank records a $20,000 loan as an asset (the borrower owes it money).
2. At the same moment, it credits the borrower’s checking account with $20,000, a new deposit and a liability for the bank.
3. The borrower pays the car dealer, whose bank account rises by $20,000. The money has moved, but it still exists, and M1 is $20,000 higher than before the loan.
4. As the borrower repays the loan, the deposits used to make the payments are cancelled against the loan. When the loan is fully repaid, that $20,000 of money is gone.

Bank lending is not unlimited. It is constrained by demand from creditworthy borrowers, by capital requirements and other regulation, by the cost of funding and holding reserves, and by central bank interest rates. Rate changes therefore reach the money supply largely through how much banks are willing to lend and how much people want to borrow.

Limits on Money Creation

A central bank cannot issue money without end. If the money supply grows much faster than the economy’s capacity to produce goods and services, each unit of money buys less. While people trust the currency, a central bank has room to expand the money supply when the economy needs it. Push too far, and inflation rises, trust erodes and people start avoiding the currency. Extreme cases are called hyperinflation.

The Evolution of American Money

Colonial Shortages and Pieces of Eight

In the 17th century, Great Britain limited the colonies’ money supply and made it illegal for them to mint their own coins. Colonists were paid in English bills of exchange redeemable only for English goods, which cut them off from trading freely with other countries.

The colonies fell back on barter, using ammunition, tobacco, nails, pelts and anything else people would accept, and collected whatever foreign coins they could. The most popular was the silver Spanish dollar, or “piece of eight,” which could be cut into eight “bits” to make change. The expression “two bits” for a quarter dollar comes from this practice.

Massachusetts Coins and Paper Money

Massachusetts defied the rules in 1652 by minting silver coins such as the Pine Tree and Oak Tree shillings. Because British law reserved coinage to the monarch, the colony dated its coins 1652, a year when England had no monarch, and kept that date on later coins. In 1690, it issued the colonies’ first paper money, called bills of credit.

The Revolution and the Continentals

When the Revolutionary War began in 1775, colonial leaders financed it with a new paper currency called the Continental. Issuers printed as much as they needed, with no fixed backing by any asset. The Continentals lost value quickly and became nearly worthless, giving rise to the phrase “not worth a Continental.” The experience made the American government wary of paper money for almost a century.

A National Monetary System

The war left most currencies in the new nation close to useless. The Constitution, ratified in 1788, gave Congress the power to coin money and regulate its value, and the Coinage Act of 1792 established the U.S. Mint and the dollar as the national unit of money. It set a bimetallic standard, under which both gold and silver defined the dollar’s value.

Removing foreign coins and competing state and local currencies took years. Many banks printed more notes than they held coin to redeem, so their notes often traded below face value, sometimes far below, depending on the issuer’s reputation.

Greenbacks and the Civil War

To fund the Civil War in the 1860s, the federal government issued $450 million in paper legal tender known as greenbacks. They were valid for public and private debts but not then redeemable in gold, and their value rose and fell with the Union’s fortunes. Confederate dollars followed the Confederacy’s fate and were worthless by the end of the war.

National Banks, Gold and the Federal Reserve

The National Bank Act of 1863 (expanded in 1864) created national banks that issued notes backed by U.S. government bonds, and the Treasury worked to push state bank notes out of circulation.

After the war, the country debated whether silver or gold should back the dollar. The Gold Standard Act of 1900 made gold the sole backing; in principle, paper money could be exchanged for its value in gold. In 1913, Congress created the Federal Reserve, giving it authority over the money supply and the interest rates on loans to banks. Domestic gold convertibility ended in 1933, and the 1971 decision completed the shift to fiat money.

Limitations of Money

Money solves the coordination problems of trade, but it carries its own weaknesses:

• Inflation risk. Fiat money’s purchasing power depends on how carefully its supply is managed, as the Continentals showed.
• Dependence on trust. If people lose faith through political crisis, war or reckless policy, a currency can collapse quickly, as Confederate dollars did.
• Imperfect store of value. Even moderate inflation steadily reduces what idle cash can buy.
• Measurement limits. Monetary aggregates change definition, as with the 2020 M1 reclassification and the end of M3 publication, so long-run comparisons need care.
• Money is not wealth. A larger money supply does not mean more output. Real output, measured by GDP, is what money ultimately buys.

Distinctions People Confuse With Money

Money vs. Currency

Currency is one form of money: the physical notes and coins, usually issued by a government, used as payment within a jurisdiction. Money is broader. It includes currency plus bank deposits and other assets that perform money’s functions.

Money vs. Legal Tender

Legal tender is the currency that law says must be accepted to settle a debt. In the United States, Federal Reserve notes and U.S. coins are legal tender. A checking deposit is money but not legal tender. Legal tender status does not by itself oblige a shop to accept cash for a purchase in every situation; that depends on the rules of the jurisdiction.

Money vs. Wealth and Income

Wealth is the total value of what a person or country owns, including homes, stocks and businesses. Income is a flow of earnings over a period. Money is the part of wealth held in spendable form at a given moment. A person can be wealthy and hold little money, or hold money with little overall wealth.

Money and Liquidity

Liquidity measures how quickly and cheaply an asset can be turned into money without losing value. Cash is the most liquid asset. Checking balances follow, then short-term securities and money market funds. Houses, cars and jewelry are much less liquid: they can be sold, but selling may take time and often requires accepting a lower price. The M1 and M2 layers are essentially a ranking by liquidity.

FAQs

The Bottom Line

Anyone holding cash, saving or reading economic news benefits from knowing what money is and what backs it. Fiat money keeps its value only while people trust the issuer and the economy keeps producing, and inflation steadily erodes idle cash. Treat money as a tool for spending and short-term saving, and remember that real wealth rests on what money can buy.