Bitcoin is a digital currency created in 2009³. It follows the ideas set out in a white paper by the mysterious Satoshi Nakamoto, whose true identity has yet to be verified³. Bitcoin offers peer-to-peer exchange of value in the digital realm through the use of a decentralized protocol, cryptography, and a mechanism to achieve global consensus on the state of a periodically updated public transaction ledger called a 'blockchain'².

The blockchain is a public ledger that records bitcoin transactions². A novel solution accomplishes this without any trusted central authority: maintenance of the blockchain is performed by a network of communicating nodes running bitcoin software⁴. Transactions of the form payer X sends Y bitcoins to payee Z are broadcast to this network using readily available software applications⁴.

Bitcoin has been criticized for its use in illegal transactions, its high electricity consumption, price volatility, and thefts from exchanges⁴. Some economists, including several Nobel laureates, have characterized it as a speculative bubble at various times⁴.

I hope that helps!