Block height, metaphorically speaking, serves as the "page number" for the blockchain's digital ledger. Each time a new transaction block is verified and appended to the chain, akin to turning a page in this ledger, the block height increases. Counting starts from the genesis block, the first in the entire blockchain network's history, labeled as block 0. Every subsequent new block carries the "fingerprint" (hash) of its predecessor, forming an ordered chain where each block's position number in this sequence denotes its block height.


Envision blockchain as a stack of building blocks, with block height resembling the layers of this stack. Unlike a Jenga game where one can remove blocks from the middle, blockchain's structure doesn't allow for the removal of any block without compromising the integrity of the whole. This ensures that each new block affirms and extends all preceding information, guaranteeing data integrity and immutability.


The pace at which block height grows isn't arbitrary; it's intimately tied to a blockchain network's average block time. For instance, Bitcoin's network theoretically produces a new block every 10 minutes on average, indicating that over time, the block height will approximately increase by 1 every ten minutes. Nonetheless, this rate isn't static; influenced by mining difficulty, which automatically adjusts based on the total computational power (hashrate) engaged in the network, maintaining a relatively stable interval between blocks.


Different blockchains, akin to different games, have their own rules (e.g., average block times and hashrate requirements), rendering direct comparisons of block heights between two distinct blockchains meaningless. Nevertheless, block height is pivotal in determining whether a blockchain copy is up-to-date. If you maintain a dataset of a blockchain on your computer, by comparing its block height to the globally recognized one, you can ascertain if your data is synchronized to the latest state. Falling behind in local block height indicates the need for your blockchain copy to "catch up," downloading and validating missed blocks to align with the network's progress.