Layer 2
A network built on top of a base chain that processes transactions cheaply and settles back to it.
Layer 2s execute transactions off the main chain in bulk, then post compressed proofs or data back to layer 1 for final settlement. Users get the cost and speed of a smaller system while inheriting the base chain’s security.
Arbitrum, Optimism, Base and zkSync are the best-known Ethereum layer 2s. The Lightning Network plays a comparable role for Bitcoin payments.