The bitcoin network is a peer-to-peer (
https://en.m.wikipedia.org/wiki/Peer-to-peer) payment network (
https://en.m.wikipedia.org/wiki/Payment_network) that operates on a cryptographic protocol (
https://en.m.wikipedia.org/wiki/Cryptographic_protocol). Users send and receive bitcoins (
https://en.m.wikipedia.org/wiki/Bitcoin), the units of currency, by broadcasting digitally signed messages to the network using bitcoin cryptocurrency wallet (
https://en.m.wikipedia.org/wiki/Cryptocurrency_wallet) software. Transactions are recorded into a distributed, replicated public database (
https://en.m.wikipedia.org/wiki/Database) known as the blockchain (
https://en.m.wikipedia.org/wiki/Blockchain_(database)), with consensus achieved by a proof-of-work (
https://en.m.wikipedia.org/wiki/Proof-of-work)system called mining. The protocol was designed in 2008 and released in 2009 as open source software (
https://en.m.wikipedia.org/wiki/Open_source_software) by Satoshi Nakamoto (
https://en.m.wikipedia.org/wiki/Satoshi_Nakamoto), the name or pseudonym of the original developer/developer group.
