Layer 2 Scaling

What is Layer 2?

Layer 2 scaling solutions are secondary frameworks or networks built on top of a base blockchain (Layer 1) that handle transactions off the main chain and periodically settle the final state back to the underlying chain. They address the scalability trilemma — the difficulty of simultaneously achieving decentralization, security, and scalability — by offloading transaction volume from the congested and expensive main chain. The major Layer 2 approaches include optimistic rollups (such as Arbitrum and Optimism), which batch transactions and assume validity unless challenged; zero-knowledge rollups (such as zkSync and StarkNet), which generate cryptographic proofs of transaction validity; state channels; and sidechains. Layer 2 solutions enable faster confirmation times, significantly lower gas fees, and higher transaction throughput while inheriting most of the security of the underlying Layer 1 chain.