<human>:  How is a blockchain ledger used?
<bot>: A blockchain ledger is used to securely store and record transactions that are shared and distributed amongst users in a decentralized network. Each transaction is secured using cryptography, making the ledger immutable and uneditable, ensuring the data within it is accurate and incorruptible. The transactions stored in the ledger are visible to all members in the network, allowing users to quickly access and verify records.