Cryptocurrency is a digital or virtual currency that uses cryptography for security and is decentralized, meaning it's not controlled by any government or financial institution. Transactions are recorded on a public ledger called a blockchain, which ensures transparency and prevents tampering. Cryptocurrencies like Bitcoin, Ethereum, and others have gained popularity due to their potential for high returns, but they also come with risks like market volatility and security threats. Some benefits of cryptocurrency include fast and global transactions, lower transaction fees, and increased accessibility. However, regulatory environments and adoption vary widely across the world.