Summary

In this chapter, we learned the limitations of Ethereum, which are scalability and high fees. Then, we saw that L2 was built to mitigate these issues. We also learned how L2 works and its relation to Ethereum. After that, we looked at examples of L2s, such as Optimism, Arbitrum, Base, Starknet, and so on. Then, we deployed a smart contract to the Arbitrum testnet blockchain. In the end, we learned about bridge applications and how we move data between Ethereum and L2. The lessons you learned in this chapter enable you to build decentralized applications with lower fees and more scalability while still depending on Ethereum security. In the next chapter, we will learn about the ERC-20 token standard and how to create tokens.