The technology that underlies blockchain and cryptocurrencies is distributed ledger technology (DLT). DLT enables secure and transparent transaction recording across a network of computers without a central authority. This decentralized approach ensures that no single entity controls the data, enhancing security and trust. Each transaction is cryptographically linked in a chain, making it immutable and verifiable. Besides cryptocurrencies, blockchain has applications in supply chain management, finance, and identity verification, showcasing its versatility in various sectors.