Transactions are verified by network nodes through encryption and recorded in a public decentralized ledger called blockchain. Bitcoin was invented by one or a group of unknown people under the name of "Satoshi Nakamoto" and released as open source software in 2009. Bitcoin was created as a reward for the mining process. They can be exchanged for other currencies, products and services. Research conducted by Cambridge University estimated that in 20 17, 2.9 million to 5.8 million different users used cryptocurrency wallets, most of which used bitcoin.
Bitcoin has been criticized for its use in illegal transactions, high power consumption, price fluctuation, theft in transactions and the possibility of becoming an economic bubble. Bitcoin is also used as an investment, although some regulators have warned investors not to use bitcoin.