A ledger is a record-keeping system that tracks transactions. In the context of cryptocurrencies, it is a key component that ensures transparency and security.Each transaction is recorded in blocks that are then linked together to form a chain, hence the term “blockchain.” Every participant in the network has access to this ledger, allowing them to verify the authenticity of transactions. This decentralized nature makes it difficult for any single entity to manipulate the data.Ledgers can be public or private. Public ledgers are open for anyone to inspect and participate, while private ledgers restrict access to specific participants. The security of the ledger is maintained through cryptographic techniques, which make it highly secure against fraud and unauthorized changes.Overall, ledgers serve as a foundation for trust in a network, allowing users to engage in transactions without needing a central authority to validate them.