Rollup
layer-2 · scalability
A Layer-2 technique that executes transactions off-chain and posts compressed proofs or data to the base chain.
Rollups batch transactions outside the base chain and publish enough data, commitments, or proofs for the base chain to settle the result. Optimistic rollups rely on fraud proofs and challenge windows; zk-rollups rely on validity proofs.
Rollups can reduce fees and increase throughput, but they add bridge risk, sequencer assumptions, data availability requirements, and different withdrawal rules. Their security depends on implementation details, not just the word "rollup."
Related terms
Layer-2
→A protocol built around a Layer-1 to move activity off the base chain while relying on it for settlement or security.
scaling · architecture
On-Chain
→Recorded or executed directly in transactions governed by a blockchain's base-layer rules.
blockchain · transaction
Off-chain
→Activity that occurs outside the base blockchain, often for speed, privacy, or cost efficiency.
blockchain
Ethereum Virtual Machine (EVM)
→The EVM is the deterministic runtime that executes smart contract bytecode on Ethereum and EVM-compatible networks.
eth · platform · smart contract