Block Depth
Also known as: Block Confirmations, Chain Depth, Finality Depth
The number of blocks added to the blockchain after a specific block, used to measure finality and security.
Block depth refers to the number of blocks that have been appended after a given block in a blockchain. It serves as a measure of how deeply embedded a block is in the chain and thus how unlikely it is to be reversed. In networks like Bitcoin, greater block depth increases confidence in transaction finality and resistance to reorganization or double-spending. For example, a transaction with six confirmations (depth of 6) is considered secure. Block depth is a key metric in both Proof of Work and Proof of Stake systems to assess immutability.