Layer 2
Layer 2 refers to a secondary framework or protocol built on top of an existing blockchain (Layer 1) to improve scalability, speed, and cost-efficiency by handling transactions off-chain or through optimized mechanisms. It operates as an overlay network that inherits the security of the underlying blockchain while enabling faster and cheaper transactions. Common implementations include rollups, state channels, and sidechains, which help alleviate congestion and high fees on base layers like Ethereum.
Developers should learn and use Layer 2 solutions when building decentralized applications (dApps) that require high throughput, low latency, or reduced transaction costs, such as in gaming, DeFi, or NFT marketplaces. It is essential for scaling blockchain ecosystems without compromising security, as it allows applications to handle more users and transactions efficiently. For example, using Optimism or Arbitrum for Ethereum-based dApps can significantly cut gas fees and improve user experience.