Glossary · B
Block
A data structure containing a batch of validated transactions on a blockchain. Each block references the previous block (via a hash), forming a chain. On Ethereum, a new block is added approximately every 12 seconds. Block size limits how many transactions can be included per block.
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How Block works in practice
A block is a batch of transactions added to the chain together. Block time sets how quickly transactions confirm, and the number of blocks since inclusion is the usual proxy for how hard the transaction would be to reverse.
Worked example
Ethereum produces a block roughly every 12 seconds. A transaction included in one is confirmed, and becomes progressively harder to reverse as subsequent blocks build on it.
Figures are illustrative and chosen to be checkable, not live market data.
The mistake that costs people money
Inclusion is not finality. Exchanges wait for multiple confirmations before crediting deposits because recent blocks can, in some circumstances, be reorganised.
Block: common questions
- What is Block?
- A data structure containing a batch of validated transactions on a blockchain. Each block references the previous block (via a hash), forming a chain. On Ethereum, a new block is added approximately every 12 seconds. Block size limits how many transactions can be included per block.
- How does Block work in practice?
- A block is a batch of transactions added to the chain together. Block time sets how quickly transactions confirm, and the number of blocks since inclusion is the usual proxy for how hard the transaction would be to reverse.
- Can you give an example of Block?
- Ethereum produces a block roughly every 12 seconds. A transaction included in one is confirmed, and becomes progressively harder to reverse as subsequent blocks build on it.
- What do people get wrong about Block?
- Inclusion is not finality. Exchanges wait for multiple confirmations before crediting deposits because recent blocks can, in some circumstances, be reorganised.