Replicated Ledger

A replicated ledger is a record of accounts or transactions that is copied in full to many separate computers, each of which keeps its own version and updates it as new entries are agreed. Rather than one bank or operator holding the master central ledger, every participant can check the same history. A consensus mechanism keeps the copies in step, deciding which new entries are valid and in what order. Public blockchains such as Bitcoin are the best-known replicated ledgers, but the idea also underlies permissioned ledgers used by banks and market infrastructure. Replication gives resilience and transparency: losing one copy loses nothing, and tampering is easy to spot. The costs are storage, bandwidth and the time needed to reach agreement. The term overlaps heavily with distributed ledger technology, though "replicated" stresses that each node holds a full copy rather than a share.