Layer 2 (L2) describes scaling systems that settle fast, cheap activity off the main chain and periodically anchor the results back to it. Rollups — which compress batches of transactions into one proof — are the dominant form on Ethereum today. Security model L2s don't reinvent trust: they post evidence to the Layer 1 so the base chain remains the arbiter of truth. Users keep custody and can always force-funds back out, though mechanics differ between optimistic and zero-knowledge rollups. Why they matter L2s lower gas costs dramatically and expand who can afford to use crypto. For analysts, they add nuance: ecosystem metrics must account for both the L1 and the L2s resting on it. Related terms Rollup, Layer 1, Gas Fees, Smart Contract, Ethereum
Layer 2 (L2) describes scaling systems that settle fast, cheap activity off the main chain and periodically anchor the results back to it. Rollups — which compress batches of transactions into one proof — are the dominant form on Ethereum today.
Security model
L2s don’t reinvent trust: they post evidence to the Layer 1 so the base chain remains the arbiter of truth. Users keep custody and can always force-funds back out, though mechanics differ between optimistic and zero-knowledge rollups.
Why they matter
L2s lower gas costs dramatically and expand who can afford to use crypto. For analysts, they add nuance: ecosystem metrics must account for both the L1 and the L2s resting on it.
Related terms
Rollup, Layer 1, Gas Fees, Smart Contract, Ethereum