Block Height

What is a Block Height?

The number of blocks confirmed in the whole history of a blockchain network, from the genesis block (or block zero) to the most recent one, is referred to as block height. This is because all other blocks, except for the genesis block, include a reference (hash) to the block that came before it, and the block height is equal to the number of blocks in the sequence. 

As a result, the genesis block has a block height of 0, while the first block mined has a block height of 1. Because blockchains are composed of blocks, one analogy that has been used to define them is to think of them as lego stacks. There is no way to eliminate a lego from the center of the stack without destroying the entire building; it's not like Jenga, where one block can be removed without affecting the others.

Therefore, the block height may be computed by dividing the time since the chain's average block duration created the blockchain. In other terms, the block height is the total number of blocks mined (or validated) since a blockchain network was created.

Diving Deep into the Concept of Block Height

Based on the mining difficulty, the average block time should be close to the goal block time. Many blockchains change the mining difficulty based on the network's aggregate hash rate such that the block duration remains relatively consistent. 

Considering the case of Bitcoin, the average block time is 10 minutes. Otherwise, the estimated block period may vary depending on the number of computational capabilities that miners dedicate to that network.

Because the estimated average period and hash rates of different blockchains differ, block height must not be directly compared. On the other hand, a blockchain replica may be termed "out of sync" if the local copy's block height differs from the globally approved block height. As a result, block height is a valuable metric for determining if a blockchain's copy is up-to-date or not.