What is cryptocurrency?

A cryptocurrency is a digital or virtual currency secured by cryptography, which makes it extremely hard to counterfeit or spend twice. Unlike traditional money issued by governments, most cryptocurrencies are decentralised, meaning no single authority controls them. Instead, transactions are recorded on a blockchain, a shared, tamper-resistant digital ledger maintained across many computers around the world. Bitcoin, launched in 2009 by an anonymous figure known as Satoshi Nakamoto, was the first and remains the best known. Thousands of others, such as Ethereum, have followed, some supporting programmable smart contracts. Cryptocurrencies can be used for payments, investment, and transferring value across borders, but their prices are often highly volatile, and they raise questions about regulation, security, and energy use.