The blockchain ledger operates as a chain of blocks containing transaction data. Each block is linked to the previous one through cryptographic hashes, ensuring that data cannot be altered without altering all subsequent blocks, thus providing tamper resistance. Transaction entries are typically stored in a format that is visible and verifiable by all participants of the network, which enhances accountability and reduces the risk of fraud. Blockchain ledgers are used in various applications, most notably in cryptocurrencies, but also in supply chain management, voting systems, and digital identity verification.