Optimistic Rollups
Optimistic Rollups are a Layer 2 scaling solution for blockchain networks, primarily Ethereum, that bundle multiple transactions off-chain into a single batch and post a summary (or 'rollup') to the main chain. They assume transactions are valid by default (hence 'optimistic') and rely on a fraud-proof mechanism where anyone can challenge incorrect transactions during a dispute period, typically 7 days. This approach significantly reduces gas costs and increases transaction throughput while maintaining the security of the underlying blockchain.
Developers should learn Optimistic Rollups when building decentralized applications (dApps) that require high transaction volumes and lower fees, such as DeFi protocols, NFT marketplaces, or gaming platforms on Ethereum. They are particularly useful for projects needing scalability without sacrificing security, as they inherit Ethereum's consensus, making them ideal for applications where trustlessness and decentralization are critical, but current mainnet limitations are prohibitive.