Bitcoin is a worldwide cryptocurrency and digital payment system8:
3 called the first decentralized digital currency, as the
system works without a central repository or
single administrator.8:19 It was invented by an unknown
person or group of people under the name Satoshi Nakamoto10 and released as open-source software in 2009.11 The system is peer-to-peer, and transactions take place between users directly, without an intermediary.8:4 These transactions are verified by network nodes and recorded in a public distributed ledger called a blockchain.