In the context of cryptocurrencies, a private ledger refers to a type of distributed ledger that is maintained by a single organization or a group of trusted participants, rather than being open to the public like the public ledger of Bitcoin, Ethereum, or other cryptocurrencies.
Private ledgers are designed to offer greater privacy, control, and security to the participants in the network, while still allowing for transactions to be recorded and verified in a decentralized way. This is achieved by limiting the access to the ledger to only authorized parties, who are granted permission to participate in the network.
Private ledgers are often used by enterprises, financial institutions, and governments to manage their own internal digital currencies or tokens, track supply chain transactions, or settle financial transactions among themselves. Examples of private ledgers include Ripple, Hyperledger Fabric, and Quorum.