Chain

Each block header contains, besides its identifier within the scope of the blockchain, a hash of the data in the block. It also contains a copy of the hash of the previous block. Because of this relationship, the a copy of the hash of the previous block, the term chain is used. This is the basis for the tamper-resistant characteristic of a blockchain.

Chain

Blockchain B contains blocks 0, 1, 2.

The ledger’s chain is a transaction log structured as hash-linked blocks of transactions. Peers receive blocks of transactions from the ordering service, mark the block’s transactions as valid or invalid based on endorsement policies and concurrency violations, and append the block to the hash chain on the peer’s file system.