The point at which a transaction becomes irreversible. Example: On Ethereum, a transaction reaches finality after several confirmations.

A temporary replacement of recent blocks due to chain competition. Example: A reorg may remove a block containing your transaction, delaying final confirmation.

The speed at which a newly created block spreads across network nodes. Example: Slow propagation increases the likelihood of reorgs.

The update to the blockchain’s global state after a transaction executes. Example: Sending tokens triggers a state transition that updates both balances.

The dynamic fee marketplace that determines which transactions get prioritized. Example: During high demand, the gas market pushes fees upward.

The limited capacity inside each block for including transactions. Example: Scarce block space leads to higher fees during peak activity.

The ability for the network to provide the data necessary to verify blocks. Example: Rollups rely heavily on strong data availability from Layer-1.

The part of the blockchain responsible for processing and executing transactions. Example: Ethereum’s Merge separated the Execution Layer from the Consensus Layer.

The layer that determines block ordering and network agreement. Example: Ethereum’s PoS validators operate primarily at the Consensus Layer.

Mechanisms that allow blockchains to interact and exchange data or assets. Example: Many bridge exploits occur due to weak XCC security.

A Layer-2 scaling method that batches transactions and posts compressed data to Layer-1. Example: Arbitrum and Optimism both use rollup architectures.

The node responsible for ordering transactions on certain Layer-2 networks. Example: If a sequencer goes offline, L2 transaction processing may slow temporarily.