What is cryptocurrency?
How cryptocurrency works without a central issuer
Cryptocurrency is digital money. It exists as records on a shared online database, not as banknotes or coins, and it’s not stored by a single bank or government agency.
Instead, the record of who owns what is kept by a network of separate computers. There's no central body like a government or central bank that issues crypto or sets policies. For example, euros have the European Central Bank, but bitcoin and others operate under fixed rules encoded in software, which anyone can review for themselves. The system's designed so no one entity can rewrite history. That's what people mean when they call it decentralized: control isn't concentrated, but shared across the network.
This shared record is the blockchain, which we break down here. Each independent machine storing a copy is known as a node. These nodes all check every transfer against the network’s agreed rules before it gets accepted.
How ownership and transfers are recorded
You won’t find physical coins or printed bills in crypto. Instead, balances are attached to addresses, which are strings of letters and numbers you can think of as a kind of account number. When you want to send funds, you approve that transfer using a private key (a code only you should know), which is your proof to the network that you control those coins. Private keys need to be protected: anyone with your key can move your funds, no questions asked.
After a transfer is approved and validated by the network, it’s stored permanently in the blockchain. This isn’t like card payments or bank transfers, where you might be able to dispute a charge or recall the money. In most cases, crypto transfers are final, with no central party able to reverse them. Your wallet (the software or gadget that holds your keys) is what actually creates and signs these transactions for you.
What you can and cannot do compared with a bank
With crypto, there’s no bank you can call to fix errors. If you lose your private key or send coins to the wrong destination, retrieving your funds is almost always impossible. Compare that to a standard bank deposit, which in many countries is protected under national schemes (to a set limit) and often supported by customer service if something goes wrong, say if a payment is accidentally made to the wrong account.
But crypto does let you send money worldwide anytime, without the need to register a local bank account or wait for business hours. That can be useful in situations where you need to send money fast or traditional payment methods aren’t available. Since there’s no one entity in control, no single group can unilaterally block payments or rewrite the system’s rules. So you gain more freedom, but are also solely responsible for your account security and for verifying transaction details.
Prices can swing sharply. The value of most cryptocurrencies can climb or drop in a matter of hours, so you could lose some or all of what you put in. For a detailed example, see our section on bitcoin, which is the most well-known cryptocurrency.
Frequently asked questions
Is cryptocurrency the same as the money in my bank?
No, it isn’t. The balance in your bank account is a promise from the bank, stored on their systems and usually backed by a government scheme up to a certain amount. Cryptocurrency is written to a blockchain database and doesn’t come with this kind of guarantee. If you keep crypto with an exchange or app, you take on additional risk, those companies could close down or be compromised. If you hold your private keys yourself, you remove company risk but are then entirely responsible for safeguarding your funds.
Can cryptocurrency be reversed if I send it by mistake?
No, not in most cases. Once a transaction is accepted by the network, it’s permanent. If you make a mistake, recovery usually depends on the receiver agreeing to send the funds back. Sometimes an exchange will cooperate with support requests, but this isn’t guaranteed. Double check the address and network every time, as correcting these errors is rarely possible.