Bitcoin (₿) is a cryptocurrency and worldwide payment system. It is the first decentralized digital as the system works without a central bank or single administrator. The network is peer-to-peer and transactions take place between users directly, without an intermediary. These transactions are verified by network nodes through the use of cryptography and recorded in a public distributed ledger called a block-chain. Bitcoin was invented by an unknown person or group of people under the name Satoshi Nakamoto and released as open-source software in 2009.
Bitcoins are created as a reward for a process known as mining. They can be exchanged for other currencies,products, and services. As of February 2015, over 100,000 merchants and vendors accepted bitcoin as payment. Research produced by the University of Cambridge estimates that in 2017, there were 2.9 to 5.8 million unique users using a #cryptocurrency wallet, most of them using bitcoin.
Etymology
The word bitcoin first occurred and was defined in the white paper that was published on 31 October 2008.It is a compound of the words bit and coin. The white paper frequently uses the shorter coin.
Units
The unit of account of the bitcoin system is a bitcoin. Ticker symbols used to represent bitcoin are BTC and XBT. Small amounts of bitcoin used as alternative units are millibitcoin (mBTC), and satoshi (sat). Named in homage to bitcoin's creator, a satoshi is the smallest amount within bitcoin representing 0.00000001 bitcoins, one hundred millionth of a bitcoin. A millibitcoin equals 0.001 bitcoins, one thousandth of a bitcoin or 100,000 satoshis.
History
Main article: History of bitcoin
On 18 August 2008, the domain name (bitcoin.org) was registered. In November that year, a link to a paper authored by Satoshi Nakamoto titled Bitcoin: A Peer-to-Peer Electronic Cash System was posted to a cryptography mailing list. Nakamoto implemented the bitcoin software as open source code and released it in January 2009 on Source-forge. The identity of Nakamoto remains unknown.
On 1 August 2017, a hard fork of bitcoin was created, known as Bitcoin Cash. Bitcoin Cash has a larger block size limit and had an identical block chain at the time of fork. On 12 November another hard fork, Bitcoin Gold, was created. Bitcoin Gold changes the proof-of-work algorithm used in mining.