Money is one of those things we use every day without stopping to question what it actually is. At its core, money is anything a community agrees to accept as payment for goods, services, or debts. That last word — agrees — is the key. Money has value because people trust it has value.
Economists define money by three functions. First, it acts as a medium of exchange: instead of trading chickens for shoes, you exchange money for shoes. Second, money is a store of value: you can earn it today and spend it next month without it rotting. Third, money is a unit of account: it gives us a common language for measuring and comparing the value of very different things.
What makes a piece of paper worth something? Nothing intrinsic. A £20 note is cotton and linen. Its value comes entirely from collective trust — trust that the government backing it is stable, that the central bank manages its supply responsibly, and that the person you hand it to will accept it in turn.
This trust is supported by legal tender laws, which require creditors to accept the currency in payment of debts, and by the credibility of the institutions that issue and manage it. When those institutions lose credibility — through reckless money printing, political instability, or runaway inflation — confidence collapses and the currency's value falls with it.
The value of money is therefore not fixed. It is a social contract, continuously renewed by collective belief in the system behind it. Understanding this helps explain why central bank independence matters, why inflation is so damaging, and why currencies in failing states quickly become worthless even when technically still legal tender.
Money is not magic. It is trust, institutionalised.