Optimistic Rollups (OR) is one of the Layer 2 solutions designed to address scalability issues on blockchains, particularly those like Ethereum. Its primary goal is to increase transaction speeds and reduce transaction fees. How it Works: Transaction Execution on Sidechain: Optimistic Rollups perform transactions on a sidechain before sending them to the main chain. This sidechain is specifically designed to process transactions quickly and at a lower cost.Signing of Transactions: At this stage, transactions only exist on the sidechain and have not been sent to the main chain yet. However, transactions go through a series of validation processes on the sidechain, and as a result, they are signed with a consolidated data (merkle root) that will be connected to the main chain.Sending Signed Transactions to the Main Chain: Once the transactions have been signed and validated on the sidechain, they are sent to the main chain. This marks the inclusion and confirmation of the transactions on the main chain.Updating Account States: When the transactions are confirmed on the main chain, account states are updated, reflecting the changes resulting from the transactions on the sidechain.Advantages:Transaction Speed: Optimistic Rollups enhance transaction speed on the main chain by utilizing fast transactions on the sidechain.Lower Costs: Transactions on the sidechain are more cost-effective, allowing users to pay lower transaction fees.Compatibility with the Ethereum Ecosystem: As an Ethereum-based solution, Optimistic Rollups is compatible with the existing Ethereum ecosystem. Disadvantages: Trust Period: Optimistic Rollups require a trust period to confirm transactions on the main chain after being processed on the sidechain, potentially leading to delays. Rollback Risk: In case of errors or attacks on the sidechain, Optimistic Rollups may roll back transactions on the sidechain. Optimistic Rollups serve as a Layer 2 solution designed to alleviate scalability concerns within the Ethereum ecosystem and operate more efficiently.