ZK-Rollup (Zero-Knowledge Rollup) is a Layer-2 scaling solution on Top of the Base Blockchain, such as Ethereum. This enhances scalability by executing multiple transactions off the chain on a different network and then compiling them into one batch posted back to the main chain. The system does not re‑run every transaction, but rather uses zero‑knowledge proofs (ZK proofs) or validity proofs to cryptographically convince that the batch is valid.
Security stays on Layer‑1, but gas costs drop, and throughput expands massively. Ultimately, the rollup makes sure that all crucial data is on chain and fully verifiable by anyone; hence, users are also protected by robust decentralization and censorship resistance. Among those protocols, there are leading Ethereum ZK‑Rollup projects such as zkSync Era, Polygon zkEVM, and Starknet.