Answer: Rollups are a layer 2 scaling solution for Tezos which allow for off-chain transactions to be processed and settled on the Tezos blockchain. The nodes used to process and settle these transactions are called "rollup nodes" and they are run by Tezos bakers, individuals, or other entities. Rollup nodes are responsible for verifying the validity of transactions and ensuring that all participants are playing by the rules. They also ensure that all transactions are properly recorded and stored on the Tezos blockchain. In order for the rollup nodes to process transactions, they must have access to the Tezos blockchain, either directly or through a third-party service provider. Additionally, rollup nodes must be kept up to date with the latest version of the Tezos protocol in order to ensure the security and integrity of the system.
