Debuting in 2009, Bitcoin became the world's first real-world cryptocurrency. Introduced by the mysterious Satoshi Nakamoto (whose true identity remains unknown), it's a digital currency that works without banks or other central authorities. Bitcoin's key feature: direct transactions. Instead of relying on banks, users can send and receive funds directly from each other over a peer-to-peer network. This allows for faster and potentially cheaper transactions, as envisioned by Nakamoto in his 2008 whitepaper, which outlined the concept of Bitcoin. While similar ideas for digital currencies existed before, Bitcoin stands out for being the first to achieve widespread adoption.