Block
TL;DR
A block is a bundle of verified Bitcoin transactions cryptographically chained to the previous block, forming the blockchain.
A block contains a header (metadata including the hash of the previous block) plus a list of transactions. Max size ~1MB (effectively up to 4MB weight with SegWit). New blocks are found on average every 10 minutes; difficulty adjustment keeps this rhythm stable as hashrate grows.
Example
Block 840,000 (20 April 2024) was the halving block: block reward dropped from 6.25 to 3.125 BTC. Blocks are publicly visible via explorers like mempool.space.
Frequently asked questions
Can a block be rejected?
Yes. If two miners find blocks simultaneously, a temporary fork occurs. The network eventually follows the longest chain; the orphaned block is discarded.
Related terms
Further reading
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