The technology that underlies blockchain for cryptocurrency transactions is a decentralized ledger system. This technology ensures that all transactions are securely recorded across a network of computers. Each transaction is grouped into blocks, which are then linked together in a chronological chain and validated through cryptographic algorithms. This structure prevents tampering and enables transparency without relying on a central authority. As a result, users can trust the system for secure transfers, reducing the risk of fraud and enhancing overall confidence in digital currencies.