The total supply of bitcoin is limited to 21 million, with around 18 million already in circulation.
Bitcoin can be bought and sold on exchanges and peer-to-peer marketplaces, and can also be used to purchase goods and services.
The market capitalization of bitcoin, which is the total value of all bitcoins in circulation, has grown to over $1 trillion.
The use of bitcoin has been criticized for its potential use in illegal activities due to its anonymity and lack of regulation.
Bitcoin transactions are recorded on a public ledger called the blockchain, which is maintained by a network of computers around the world.