The informative part of a block which contains its metadata and the most fundamental details about the block’s transaction.
A block header is a part of a block, that is, the computer file that records transactions on a blockchain. This part serves the function of recording the summary of the transaction on the block and storing the metadata. Thus, viewing the information on the block header provides a user with an idea of the essential details about the transaction, including the time it took place and the identifying hash of the previous block’s header.
A typical block header has 6 components. These include the software version number, the previous block’s hash, the root hash of the Merkle tree which consists of the aggregated record of all transactions, the time the transaction took place, the difficulty, and nonce.