Arbitrum is a layer 2 scaling solution for Ethereum, aiming to enhance its scalability and transaction efficiency. It employs optimistic rollups, a technique that aggregates multiple transactions off-chain before submitting a compressed proof to the Ethereum mainnet. By doing so, Arbitrum significantly improves transaction speeds and reduces fees compared to the Ethereum base layer. It maintains compatibility with the Ethereum Virtual Machine (EVM), allowing developers to deploy their smart contracts seamlessly. Arbitrum's approach provides a scalable infrastructure for decentralized applications (dApps) without sacrificing the security and decentralization features of Ethereum, fostering a more accessible and user-friendly environment for Ethereum-based projects.