A header chain is a sequence of block headers that forms the backbone of a blockchain. Each block header contains important metadata about a block, including the previous block’s hash, a timestamp, the nonce, and the Merkle root of the transactions in that block.The primary function of the header chain is to ensure the integrity and continuity of the blockchain. By referencing the hash of the previous block, each block header creates a link to its predecessor, making it nearly impossible to alter past transactions without changing all subsequent headers. This structure helps maintain consensus among network participants, as all nodes can verify the chain’s integrity by checking these headers. When a new block is added to the chain, it must reference the correct hash of the most recent block, reinforcing the security and trustworthiness of the network.In summary, the header chain is crucial for ensuring that the blockchain remains secure, transparent, and resistant to manipulation.