Bitcoin (BTC) is the first and largest cryptocurrency, a digital currency that runs on a decentralised network of computers instead of a bank or government. It was introduced in 2008 by the pseudonymous Satoshi Nakamoto, and the network went live in January 2009. Transactions are recorded on a public ledger called the blockchain and secured by miners through a process known as proof of work. Bitcoin's supply is capped at 21 million coins, which is why many people compare it to digital gold and use it as a store of value. You can use BTC to send value across borders, hold it for the long term, or trade it against other assets.