Block
PROTOCOLDEFINITION
A batch of transactions bundled together, verified, and added to the blockchain roughly every ten minutes.
Miners collect pending transactions from the mempool, pack them into a candidate block, and race to find the proof-of-work solution that lets them add it to the chain. The winner broadcasts the block and collects the block reward plus fees.
Each block contains a cryptographic fingerprint of the previous one — that linkage is what makes rewriting history effectively impossible and gives the "chain" its name.
IN A SENTENCE
“Her transaction confirmed in the next block, about eight minutes after she sent it.”
Key facts
Common questions
Why ten minutes?
A design compromise between confirmation speed and the time needed for blocks to propagate worldwide without constant conflicts.
What is block height?
The count of blocks since the first one — a block’s position in the chain, used like a timestamp.