Bitcoin, also known by its symbol BTC, is the first and most well-known cryptocurrency. It was created in 2009 by an anonymous person or group known as Satoshi Nakamoto. Bitcoin is a decentralized digital currency, which means it is not controlled by any central authority like a government or a bank. It is based on a technology called blockchain, which is a public ledger of all transactions that have ever occurred on the network.

Bitcoin can be used for various purposes, such as online transactions, remittances, and as a store of value. It has gained significant popularity and adoption over the years, with many businesses and individuals now accepting BTC as a form of payment. Bitcoin's value is determined by supply and demand, and its price can be quite volatile, making it an attractive investment opportunity for some and a risky one for others.