How can blocks be identified?

Blocks can be identified by their block height and block header hash.

In a blockchain, blocks are typically identified through a combination of their block number and a unique identifier called a cryptographic hash. Here’s a brief explanation:

1. Block Number: Each block in a blockchain is assigned a unique sequential number, known as the block number. This number indicates the position of the block within the blockchain’s chronological order. The first block is often referred to as the “genesis block,” and subsequent blocks are numbered sequentially.
2. Cryptographic Hash: Each block contains a cryptographic hash, which is a fixed-size string of characters generated by a cryptographic hash function (such as SHA-256). The hash is unique to the block’s content and acts as a digital fingerprint. Even a small change in the block’s data would result in a completely different hash.

To identify a specific block, you would typically refer to its block number and the cryptographic hash of its contents. This ensures that each block is uniquely identified and that any tampering with the data in a block would be immediately detectable due to the change in the cryptographic hash.

Blockchain networks use these identifiers to maintain the integrity and security of the chain, allowing participants to easily reference and verify specific blocks within the decentralized ledger.