What Is Money?
Plain English
Money is what people use to buy and sell things and to save for later. Prices tend to rise over time, so cash sitting still tends to buy a little less each year.
What is it?
Money is anything widely accepted as payment for goods, services, or debts. Economists describe it as serving three functions: a medium of exchange (something people accept in trade), a unit of account (a common way to price and compare things), and a store of value (something that holds worth so it can be used later).
Why does it matter?
Understanding what money actually does helps explain why holding too much idle cash has a real cost (lost purchasing power to inflation), and why concepts like compound growth and diversification exist — they're ways of preserving or growing the store-of-value function over time.
How does it work?
In the U.S., money exists mainly as physical currency and as digital bank deposits. The Federal Reserve influences the money supply and short-term interest rates, which in turn affect borrowing costs and, indirectly, prices throughout the economy.
Risks and limitations
Cash loses purchasing power over time due to inflation — see the Inflation lesson for the math. Money is also not the same as wealth: wealth includes assets like property, investments, and retirement accounts, minus what you owe (see Net Worth, below).
Questions to ask a professional
How much of my savings should sit in cash versus other accounts? How does inflation affect my specific goals and timeline? A qualified professional can help translate these general concepts into a plan for your circumstances.