Cryptocurrency is a digital or virtual currency that uses cryptography for security. It operates independently of a central bank or government. Bitcoin, the first and most widely used cryptocurrency, was created in 2009. Other popular cryptocurrencies include Ethereum, Ripple, and Litecoin. Cryptocurrency transactions are recorded on a public digital ledger called a blockchain, which allows for secure and transparent transfers without the need for a third party intermediary. However, the value of cryptocurrencies can be highly volatile and they are not widely accepted as a form of payment by merchants.