A rollup aggregator is a layer 2 solution designed to enhance blockchain scalability and reduce transaction costs. It operates by bundling multiple transactions into a single batch, which is then processed on the main blockchain. This significantly decreases the load on the base layer and improves throughput.There are generally two types of rollups: optimistic and zero-knowledge (ZK) rollups. Optimistic rollups assume transactions are valid by default and only verify them if fraud is suspected. ZK rollups, on the other hand, use cryptographic proofs to verify transactions without needing to reveal the underlying data.By consolidating transactions, rollup aggregators not only enhance speed but also lower fees for users. They can facilitate faster interactions, which is particularly beneficial for decentralized applications and services that require high transaction volumes.In summary, rollup aggregators play a crucial role in making blockchain networks more efficient and user-friendly, allowing for a broader range of applications and user engagement.