It’s well known that many blockchains have scalability and congestion problems. These issues have wide-ranging effects from slow transaction times, to increased transaction fees, and degraded user experience.
One solution is for web3 to be multi-chain using L2 (layer two) chains. Ethereum L2s, such as Optimism, Arbitrum, and Polygon, build on top of the Ethereum network but are faster and cheaper than Ethereum. As a tradeoff, however, they are often less secure than Ethereum. That’s why L2s handle the day-to-day user activities, while still relying on Ethereum L1 as a behind-the-scenes foundation for a secure and decentralized settlement and data availability layer.