Definition
Block height is a numerical value that shows a block’s position within a blockchain, starting from the first block known as the genesis block. Each new block added to the blockchain increases the block height by one, so the height directly reflects how many blocks exist in the chain.
This metric is commonly used to reference a specific block and to describe how far a blockchain has progressed over time. Because every valid chain has a clear sequence of blocks, block height helps identify the current state of the blockchain and distinguish between different versions of the chain if they appear.
Context and Usage
Block height is closely related to other basic blockchain concepts such as a block, the overall blockchain, and block time, which is the average time between new blocks. When people talk about waiting for a certain number of block confirmations, they are referring to additional blocks being added on top of the block at a given height.
Block explorers typically display the latest block height so users and nodes can see how many blocks have been created so far. Nodes rely on block height, along with other rules, to track the longest valid chain and to stay synchronized with the rest of the network.