Bitcoin (BTC) is a decentralized digital currency that operates without a central authority or government. It was introduced in 2009 by an anonymous individual or group known as Satoshi Nakamoto. Bitcoin uses blockchain technology to record transactions securely and transparently on a public ledger. Limited to 21 million coins, its scarcity contributes to its value. It allows peer-to-peer transactions across borders with low fees and high speed. Bitcoin is often viewed as "digital gold" due to its potential as a store of value. Despite price volatility, it has become a popular investment and a cornerstone of the cryptocurrency market.