What Does "Immutable Record" Mean?
An immutable record ensures data cannot be changed once recorded. In Bitcoin's context, its blockchain serves as an immutable ledger, meaning once a transaction is added, it cannot be altered without altering every subsequent block, which is practically infeasible. The cryptographic SHA-256 hash function primarily enforces this quality. Each block's hash includes the previous block's hash; thus, any change to a block invalidates all following blocks. Bitcoin's immutability is vital for its trustworthiness, ensuring transparency and data integrity in financial transactions.