ZK-Rollups: Where This Meets Real Blockchains · 1/2
Proving a batch of transactions at once
A ZK-rollup bundles hundreds or thousands of transactions off the main chain, then generates a single zero-knowledge proof that the resulting state change is valid, correct according to every rule of the system, without the main chain needing to re-execute every individual transaction. The main chain just verifies one small proof instead of redoing all that work.
This is fundamentally different from an optimistic rollup, which assumes transactions are valid unless someone proves otherwise within a challenge window. A ZK-rollup proves validity upfront, mathematically, before the batch is ever accepted, which is why ZK-rollups don't need a waiting period for withdrawals the way optimistic rollups typically do.