Arbitrum is an Ethereum Layer2 scaling solution created by the Offchain Labs team based on Optimistic Rollup technology. Arbitrum leverages the ability to communicate between L1 and L2, allowing any form of Ethereum asset to be transferred between Layer 1 and Layer 2 without trust. Although Arbitrum transactions are still settled on Ethereum, Arbitrum only submits the raw transaction data to Ethereum, with execution and contract storage occurring off-chain, so the gas fee required on Arbitrum is very small compared to the mainnet, and the contracts are fully compatible with no gas limit.