Bitcoin is the first decentralized digital currency, created in 2009 by an anonymous developer or group of developers known as Satoshi Nakamoto. It functions on a peer-to-peer network, allowing users to send and receive payments without the need for centralized intermediaries like banks. Bitcoin transactions are recorded on a public ledger called the blockchain, which ensures transparency and security. The supply of Bitcoin is capped at 21 million, making it deflationary by design.