Bitcoin is a type of cryptocurrency that was created in 2009 by an anonymous person or group known as Satoshi Nakamoto. It allows for peer-to-peer transactions over the internet without the need for a central authority, making it a revolutionary form of digital money. Transactions made with Bitcoin are recorded on a public ledger called the blockchain, which ensures transparency and security. Bitcoin has gained popularity as both a medium of exchange and a store of value, often referred to as 'digital gold' due to its limited supply and increasing demand.