Off-chain execution

A key feature of Rollups is that transactions are executed off-chain. This means that the Layer 2 network can handle transactions with other users or smart contracts instead of the underlying blockchain. Due to the smaller number of verification nodes and more powerful hardware, this will greatly increase the transaction throughput of the Layer 2 network compared to the underlying blockchain.

The underlying blockchain only needs to calculate the proof submitted to the smart contract to verify the activities in the Layer 2 network (note: in the case of optimistic rollups, verification is only required when differences occur), and the unexecuted original transaction data Stored as calldata. In short, the blockchain no longer needs to perform so many computing tasks, nor does it need to store so much transaction data on Layer 2, so it can reduce the cost of each transaction.