What is the Block Header?
The block header is made up of metadata (Data about data).
- The first part: There is a citation to a former block hash, which joins this block to the earlier block in the blockchain.
- The second part: In this, metadata such as timestamp, and nonce correlate to the mining race.
- The third part: In this metadata is the Merkle tree root. This tree root is a data structure that is utilized to efficiently compile all the transactions in the block.
The Block Identifiers
There are two ways the blocks can be identified. These are cryptographic hash and block height.
The primitive identifier of a block is its cryptographic hash. It is also known as a digital fingerprint which is built by hashing the block header twice through the SHA256 algorithm. The resulting 32-byte hash is described as the block hash but is more precisely the block header hash because is utilized to calculate it. For example, 000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f is the block hash of the first bitcoin block ever created. The block hash recognizes a block and can be autonomously determined by any node by directly hashing the block header.
Another way to recognize a block is by its location in the blockchain. This is described as the block height. The first block created is at block height 0 (zero) and is the same block that was earlier cited by the next block hash is 000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f.
What is the Genesis Block?
The first block in the blockchain is known as the genesis block. This was built in the year 2009. It is the universal parent of all the blocks in the blockchain. In other words, if people begin at any block and watch the chain counterclockwise then they will ultimately come at the genesis block.
Every node perpetually begins with a blockchain of at least one block because the genesis block cannot be modified. Every node always recognizes the genesis block’s hash and structure. It also recognizes its fixed time when it was created and even its single transaction. Thus, every node has the starting point for the blockchain, a secure “root” from which to build a trusted blockchain.
Blockchain technology is a unique invention that has caused the much-required security and protection in the cyber world.