Arbitrum (ARB), a layer-2 scaling solution for Ethereum, employs optimistic rollup technology.
The Arbitrum blockchain uses rollups to combine multiple transactions into one, lowering on-chain transaction costs and boosting scalability. Thus, Arbitrum achieves a throughput of up to 40,000 transactions per second by this method, significantly decreasing gas costs on the Ethereum mainnet.
ARB is its native governance token, primarily used for protocol governance.