According to ethereum.org: “Layer 2 (L2) is a collective term to describe a specific set of Ethereum scaling solutions. A layer 2 is a separate blockchain that extends Ethereum and inherits the security guarantees of Ethereum.” On top of layer 1s, layer 2 refers to a collection of off-chain solutions (distributed blockchains) that alleviate scale and data bottlenecks. Consider a restaurant kitchen where just a few orders could be filled every hour if each order had to be completed by a single worker from start to finish before being confirmed and delivered. But layer 2s are more like prep stations, where each station can concentrate and do each operation much more quickly. For example, there is a station for washing and chopping food, a station for cooking, and a station for assembling the dishes. A last person can validate the order by comparing each assembled dish to the order when the time is appropriate.
What are the different types of Layer 2
Generalized Layer 2:
boba — Boba is an Optimistic Rollup originally forked from Optimism which is a scaling solution that aims to reduce gas fees, improve transaction throughput, and extend the capabilities of smart contracts. Note: State validation in development
Arbitrum — boosting the speed while adding privacy and addt’l features, it’s the most EVM-compatibile layer 2 solution today. Arbitrum is an Optimistic Rollup that aims to feel exactly like interacting with Ethereum, but with transactions costing a fraction of what they do on L1. Note: Fraud proofs only for whitelisted users, whitelist not open yet
Optimism — Optimism is a fast, simple, and secure EVM-equivalent optimistic rollup. It scales Ethereum’s tech while also scaling its values through retroactive public goods funding. Note: Fault proofs in development
Application specific layer 2:
Zk-sync — zkSync is a user-centric zk rollup platform from Matter Labs. It is a scaling solution for Ethereum, already live on Ethereum mainnet. It supports payments, token swaps and NFT minting.
ZkSpace — The ZKSpace platform consists of three main parts: a Layer 2 AMM DEX utilizing ZK-Rollups technology called ZKSwap, a payment service called ZKSquare, and an NFT marketplace called ZKSea.
Loopring — Loopring’s zkRollup L2 solution aims to offer the same security guarantees as Ethereum mainnet, with a big scalability boost: throughput increased by 1000x, and cost reduced to just 0.1% of L1.
Aztec — Aztec Network is the first private zk-rollup on Ethereum, enabling decentralized applications to access privacy and scale.
Mike Mendoza, https://twitter.com/0xdecaff
