Blockchain
Ethereum L2
Also known as: Ethereum Layer 2, L2, Layer 2 rollup
A blockchain that batches transactions and periodically settles them to Ethereum's Layer 1, inheriting L1's security at a fraction of the cost.
An Ethereum Layer 2 (L2) is a secondary chain that runs on top of Ethereum's Layer 1 (L1). L2s batch user transactions, execute them off of L1, and periodically commit summaries of their state back to L1 for settlement. Because the settlement data inherits L1's security, users get Ethereum-grade trust at L2-grade cost.
Two main L2 architectures exist: optimistic rollups (like Optimism, Arbitrum, and Base) and zk-rollups (like Starknet, zkSync, and Polygon zkEVM). Optimistic rollups assume transactions are valid and challenge fraudulent ones via a dispute-resolution window; zk-rollups prove validity cryptographically up front.
LearnCoin anchors credential Merkle roots on Base, an optimistic rollup built on the OP Stack. When a verifier checks a credential, they walk the Merkle path to the root and confirm the anchoring transaction landed on Base — trust flows via Base's fraud-proof settlement back to Ethereum L1.