Block header

The block header of a block in Bitcoin comprises of metadata about the block. Consider the following:

• Bitcoin version: This field contains the Bitcoin version number.
• Previous block hash: The previous block's hash is required to create the new block's hash.
• Merkle root: This is the hash of the root of the Merkle tree of the current block's transactions.
• Timestamp: This is the timestamp of the block in UNIX.
• Mining difficulty: Mining is a crucial part of the blockchain ecosystem in Bitcoin. There is a difficulty target for mining, which is mentioned in the header.
• Nonce: Blockchain adds deviations in each block; these are known as nonce. Take a look at this diagram: