$BTC Bitcoin is a decentralized cryptocurrency and a payment system that does not require a central bank or single administrator for its operation,[4]ā[5]ā as it operates through a network of peer-to-peer nodes that verify transactions using cryptography and record them in a public ledger called the blockchain. Consensus among nodes is achieved through a computationally intensive process based on the proof-of-work system known as 'mining,' which ensures the security of the blockchain