Parallel Network is a Layer 2 scaling solution built on top of Ethereum, powered by Arbitrum's Nitro stack. Parallel Chain is EVM-compatible which means you can do anything on Parallel Network that you would be able to do on Ethereum mainnet - deploy contracts, use Web3 apps, interact with wallets, etc. However, because Parallel Chain is a rollup, transactions will be cheaper and faster than Ethereum. Parallel Network is an optimistic rollup which means it inherits many security properties from Ethereum. More specifically, Parallel Network is built using Arbitrum's Nitro stack. Nitro is the latest version of Arbitrum technology which includes a complete optimistic rollup system, a sequencer, token bridges, fraud proofs, and more.