All terms
A batch of transactions added to the chain at one time.
A block is a bundle of transactions plus a header containing a timestamp, a reference to the previous block, and a fingerprint of the contents. Blocks arrive on a schedule that depends on the network: about ten minutes on Bitcoin, twelve seconds on Ethereum, under half a second on Solana.
Block space is a finite resource. When more people want to transact than a block can hold, fees rise, because you are bidding for a limited amount of room.
Ethereum blocks have a gas limit. When demand exceeds it, the base fee rises automatically until demand fits.
That a block is a fixed amount of time. It is a fixed amount of space, filled when the network decides to close it. On a busy chain the block is full and your transaction waits for the next one, which is why paying more moves you forward.
Common questions
How big is a block?
What happens to transactions that do not fit in a block?
Where to go next
More foundations terms
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