L2 Rollup
Also known as: Layer 2 Rollup, Ethereum Rollup, Off-chain Scaling Solution
A Layer 2 scaling solution that executes transactions off-chain and posts compressed data to Layer 1 for security.
L2 rollups are Layer 2 solutions designed to scale blockchains like Ethereum by processing transactions off-chain while inheriting security from Layer 1. Rollups execute transactions on a separate network, batch them, and submit a summary to the main chain. Two types exist: Optimistic Rollups (e.g., Optimism, Arbitrum) and ZK-Rollups (e.g., zkSync, Starknet). The difference lies in how they verify transactions—ZK-Rollups use cryptographic proofs, while Optimistic Rollups rely on fraud detection windows. Rollups reduce fees, increase throughput, and preserve Ethereum’s decentralization model.