Block Time
The average time between blocks on a network, which sets how often new transactions get their first confirmation.
Proof-of-work chains hit a target average by adjusting difficulty, so Bitcoin aims at roughly ten minutes per block regardless of how much hardware is running. Proof-of-stake chains usually run on fixed slots, so Ethereum has a twelve-second slot in which the assigned proposer either produces a block or misses its turn. Shorter block times give faster inclusion but produce more competing blocks that get discarded, and they accumulate state and history faster, raising the cost of running a node. Readers meet block time when comparing chains and when estimating how long a deposit will take to clear.
In practice
Bitcoin targets an average of about ten minutes per block through difficulty adjustment, while Ethereum uses fixed twelve-second slots that can be empty if a proposer fails to act.
The common misunderstanding
A short block time is not the same as fast settlement; a chain with quick blocks may still require many blocks or an explicit finality rule before a payment is treated as settled.
The figure this maps to
The average number of seconds between new blocks being added to the chain.
Limits: Target and realized block time are different things, and providers report both under the same label. Proof-of-work block discovery is a memoryless random process, so short samples routinely show intervals far from the target, and a sharp change in hash rate skews the realized average until the next…