Cryptocurrency is a digital or virtual form of currency that relies on cryptography for security. Unlike traditional money issued by central governments, most cryptocurrencies operate on decentralized networks based on blockchain technology. A blockchain is a secure, distributed ledger that records transactions across many computers so that the record cannot be altered retroactively. The first and most well-known cryptocurrency is Bitcoin, which was created in 2009. Today, there are thousands of other options, often called altcoins, including Ethereum and Solana. These digital assets are used for online purchases, global money transfers, and speculative investments. While cryptocurrency offers benefits like lower transaction fees and financial inclusion, it also carries significant risks. The market is highly volatile, meaning prices can fluctuate wildly in short periods. Additionally, security concerns and evolving government regulations remain major challenges. Ultimately, crypto is transforming how society interacts with money.