Bitcoin (BTC) is a cryptocurrency, a virtual currency designed to act as money and a form of payment outside the control of any one person, group, or entity, thus removing the need for third-party involvement in financial transactions. It is rewarded to blockchain miners for verifying transactions and can be purchased on several exchanges.

Bitcoin was introduced to the public in 2009 by an anonymous developer or group of developers using the name Satoshi Nakamoto.

It has since become the most well-known cryptocurrency in the world. Its popularity has inspired the development of many other cryptocurrencies. These competitors either attempt to replace it as a payment system or are used as utility or security tokens in other blockchains and emerging financial technologies.

In August 2008, the domain name Bitcoin.org was registered. Today, at least, this domain is WhoisGuard Protected, meaning the identity of the person who registered it is not public information.

Bitcoin isn't too complicated to understand as a form of digital currency. For example, if you own a bitcoin, you can use your cryptocurrency wallet to send smaller portions of that bitcoin as payment for goods or services. However, it becomes very complex when you try to understand how it works. In October 2008, a person or group using the false name Satoshi Nakamoto announced to the cryptography mailing list at metzdowd.com: "I've been working on a new electronic cash system that's fully peer-to-peer, with no trusted third party." This now-famous white paper published on Bitcoin.org, entitled "Bitcoin: A Peer-to-Peer Electronic Cash System," would become the Magna Carta for how Bitcoin operates today.