Introduction to Layer 2

Ethereum became the default settlement layer for DeFi, NFTs, and on-chain apps — but success created a bottleneck. Every transaction competes for limited block space on Layer 1, and when demand spikes, fees rise for everyone.

Rollups are the dominant L2 design today. They batch thousands of L2 transactions, post compressed data to Ethereum, and inherit L1 security because anyone can verify what happened.

This course walks through why scaling matters, how rollups work, and what you need to know to use L2 networks safely.