A ledger in blockchain is an immutable digital record that securely stores transaction data across a decentralized network. Unlike traditional financial ledgers controlled by central banks, blockchain ledgers operate transparently, allowing real-time transaction verification, auditability, and fraud prevention. The emergence of public ledgers, private blockchains, and hybrid blockchain models caters to different use cases in finance, healthcare, and government sectors. Investors monitor blockchain ledgers for on-chain activity, whale transactions, and DeFi protocol liquidity to assess market movements and investment trends.