Ethereum is secure and decentralised, but it can also be slow and expensive when demand is high. Layer 2 networks (L2s) are the main answer to that problem: they process transactions away from Ethereum’s main chain, then settle back to it, keeping most of the security while cutting cost.<\/p>\n
Every transaction on Ethereum’s base layer (Layer 1) is processed by thousands of nodes, which is what makes it secure \u2014 and what makes it congest and get pricey under load. Rather than change that core, the ecosystem chose to scale “on top” of it.<\/p>\n
The dominant L2 design is the rollup<\/em>. It executes many transactions off-chain, bundles (“rolls up”) them into a compressed batch, and posts that batch to Ethereum. Because Ethereum only has to verify the batch rather than every individual transaction, fees drop sharply. There are two broad flavours: optimistic rollups<\/strong>, which assume batches are valid unless challenged, and zero-knowledge (ZK) rollups<\/strong>, which prove validity with cryptography up front.<\/p>\n For most people, an L2 feels like a cheaper, faster version of Ethereum with its own token gas and bridges. The trade-offs to understand are the extra step of bridging assets across, differing security and withdrawal models between L2s, and a more fragmented experience. As the technology matures, these rough edges are smoothing out.<\/p>\nWhat it means for users<\/h2>\n