The Arbitrum blockchain is a Layer 2 scaling solution designed to enhance Ethereum’s performance by offering faster and cheaper transactions. The network was officially launched in August 2021, Built by Offchain Labs, having founders as Ed Felten, Steven Goldfeder, and Harry Kalodner. Arbitrum uses Optimistic Rollups to bundle multiple transactions off-chain before submitting them to Ethereum, significantly reducing gas fees while maintaining security. 

Arbitrum's native token, ARB, is used for governance, allowing token holders to participate in decision-making for network upgrades and development. For tracking transactions and network activity, users rely on the Arbitrum Explorer (arbscan.io), which provides real-time data on blocks, transactions, and smart contracts. These tools help developers and users navigate the blockchain efficiently, ensuring transparency and easy access to on-chain information. 

Projects on the Arbitrum blockchain include GMX (a decentralized perpetual exchange), Radiant Capital (a lending protocol), and TreasureDAO (a gaming ecosystem).