Arbitrum (ARB) vs Optimism (OP)

Arbitrum is a layer 2 solution for Ethereum based on Optimistic Rollup technology to improve the scalability of the main network and offer lower transaction fees. The Arbitrum teams are developing two products: Arbitrum One and Arbitrum Nova, two layer 2 blockchains. Unlike other Optimistic Rollups, Arbitrum uses an enhanced fraud proof system as well as its own virtual machine (Arbitrum Virtual Machine).

Optimism is an ecosystem of scalability solutions for the Ethereum blockchain. The main blockchain is the OP Mainnet, a layer 2 network based on Optimistic Rollup technology that enhances Ethereum's capacity while offering lower transaction fees. The Optimism teams also provide the OP Stack, a set of development tools that facilitate the creation of OP Chains, blockchains based on Optimism technology that form the Superchain, a galaxy of interconnected and interoperable blockchains.