Block height is the total number of confirmed blocks in a blockchain network’s history, starting with the genesis block (also known as block zero) and ending with the most recent block. Besides the genesis block, all blocks contain a reference (hash) to the block that came before it, and the block height is the sum of all those numbers. Therefore, the genesis block has a block height of #0, while the first block to be mined has a block height of #1.
The analogy of thinking of blockchains as stacks of legos is sometimes used to describe them because blockchains are built up of blocks. However, it is not like Jenga, where you can sneak a block out without jeopardizing the others, where you can remove a lego from the center of the stack without ruining the entire construction.
As a result, the block height may be computed by dividing the time from the blockchain’s start by the chain’s average block duration. In other words, the block height is the total number of blocks mined (or verified) on a specific blockchain network.
