Bitcoin is a decentralized cryptocurrency and public blockchain that was hailed as the world’s first decentralized peer-to-peer digital payment system. Payments occur through transactions on a public distributed ledger called a blockchain. Transactions are verified through the use of nodes which utilize computational power to record the transactions as entries in the blockchain. This is collectively referred to as “mining”, which is also how new bitcoins are created. Miners repeatedly verify and collect transactions. New groups of transactions are bundled into what is called a block and are secured through a protocol called proof-of-work. Each block added to the blockchain generates new bitcoins which, alongside transaction fees, is rewarded to the miner who found the new block. Released in 2009 by an unknown person or group under the name Satoshi Nakamoto, Bitcoin follows the open source model, uses the popular SHA-256 as hash function, and provides users with the benefit of being pseudonymous. Supply is limited to exactly 20,999,999.9769 bitcoins.
The unit of value of the Bitcoin blockchain is a bitcoin (BTC/XBT). It can be bought and traded on the vast majority of crypto asset exchanges on the internet.