Cryptocurrency is a form of digital or virtual money that uses cryptography for security and operates on decentralized networks called blockchains. Unlike traditional currencies controlled by governments or banks, cryptocurrencies are maintained by distributed computers around the world. Bitcoin, the first cryptocurrency, introduced the idea of peer-to-peer digital payments without intermediaries. Today, thousands of cryptocurrencies exist, such as Ethereum, which supports smart contracts and decentralized applications. Crypto offers benefits like transparency, fast global transactions, and financial inclusion, but it also carries risks including price volatility, regulatory uncertainty, security threats, and misuse. Overall, cryptocurrency is reshaping modern finance.