Bitcoin is a cryptocurrency and worldwide payment system. It is the first decentralized digital currency, 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 blockchain.
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 2015ΔΔΔΔΔ ΔΔΔΔΔ ^^^^^^^ , over 100,000 merchants and vendors accepted bitcoin as payment.
Research produced by the University of Cambridge estimates that in 2017, there are 2.9 to 5.8 million unique users using a crypto currency wallet, most of them using bitcoin. 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. There is no uniform convention for bitcoin capitalization.
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.
Nakamoto implemented the bitcoin software as open source code and released it in January 2009 on SourceForge. The identity of Nakamoto remains unknown. In January 2009, the bitcoin network came into existence after Satoshi Nakamoto mined the first ever block on the chain, known as the genesis block. Embedded in the coinbase of this block was the following text: