Rollups
Rollups are a layer-2 scaling solution for blockchain networks that execute transactions off-chain and then post compressed data or proofs to the main chain (layer-1) for security and finality. They bundle or 'roll up' multiple transactions into a single batch, reducing congestion and fees on the underlying blockchain. There are two main types: optimistic rollups, which assume transactions are valid unless challenged, and zero-knowledge rollups, which use cryptographic proofs to verify correctness.
Developers should learn about rollups when building decentralized applications (dApps) that require high throughput and low transaction costs, such as DeFi protocols, gaming platforms, or NFT marketplaces, especially on Ethereum where scalability is a bottleneck. They are essential for improving user experience by enabling faster and cheaper transactions while leveraging the security of the main chain, making them a key technology in the blockchain ecosystem for scaling solutions.