Block header: a concise summary of a block
A block header summarizes a block using a small number of fixed fields and links it to the previous block and the transactions in the block. It participates in proof of work and enables lightweight clients to perform limited verification without storing the complete blockchain.
What is a block header?
A block header is the summary portion of a block. It stores core identifying information and metadata rather than the complete transaction list. It records the block’s approximate creation time, its connection to the previous block, and a hash value derived from all transactions to summarize the block’s contents.
Fields of a Bitcoin block header
A Bitcoin block header is fixed at 80 bytes and contains six fields: version, previous block hash, Merkle root, timestamp, difficulty target, and nonce. The version reflects the consensus rules, the previous block hash links the blocks, the Merkle root commits to the transaction set, and the last two fields are used for proof of work.
Why is it important?
Miners perform double SHA-256 hashing on the block header, searching for a result that satisfies the difficulty target; the resulting hash also becomes the block identifier. A lightweight client can store block headers and obtain a Merkle proof to check whether a specific transaction was included, but inclusion of a proof does not equal independently completing validation of the entire chain and all transaction rules.
Original Tutorial
https://www.binance.com/zh-CN/academy/glossary/block-header
Bitcoin block structure and inclusion proofs
https://developer.bitcoin.org/devguide/block_chain.html
Mark it complete when you understand it.
Opening a lesson does not complete it automatically. You can change its status at any time.