Arbitrum is an Optimistic Rollup protocol designed for the Ethereum blockchain. The Arbitrum Rollup chain is a super scaled Layer 2 (L2) chain, and interacting with Arbitrum feels exactly like interacting with Ethereum without compromising on security or decentralization, except:
Transactions are significantly faster.
Gas fees are significantly lower.
How do I get started on Arbitrum?
Note: Arbitrum's native token is also $ETH. To use your ETH on Arbitrum mainnet, you will need to bridge ETH from Ethereum Mainnet to Arbitrum One Mainnet.
Arbitrum has an official tutorial on bridging ETH from Ethereum Mainnet into Arbitrum.
Arbitrum Bridge Tutorial
Official Arbitrum Bridge Tutorial
To get started, you first need a Web3 wallet, such as Metamask.
A crypto wallet & gateway to blockchain apps | MetaMask