Arbitrum is a scaling solution on Ethereum that utilizes Optimistic Rollup. It allows users to enjoy faster speeds and cheaper transaction costs when interacting with web3 dApps.

There are currently 2 Arbitrum chains:

Arbitrum One: The main applications are concentrated on Arbitrum One, most of which are DeFi protocols.

Arbitrum Nova: Leveraging a weaker trust setup in exchange for lower fees for high-volume applications such as gaming and social.

The project consists of the following parts:

Arbitrum Nitro: Optimistic Rollup underlying technology that supports all Arbitrum products.

Arbitrum rollup: The main use case for Nitro technology and Arbitrum One. Arbitrum rollup orders and batches transactions to be published to Ethereum, thereby inheriting the security of Ethereum.

Arbitrum AnyTrust: A variant of Arbitrum Nitro that trades a weaker trust setup for lower transaction costs and faster withdrawals. AnyTrust relies on an external Data Availability Committee (DAC) for data availability. Arbitrum Nova uses Arbitrum AnyTrust.

Orbit: A permissionless platform for launching custom L3 chains on the Arbitrum ecosystem using the Arbitrum Nitro underlying technology.