A layer 2 is a blockchain network that runs on top of a base chain (layer 1) such as Ethereum. It processes transactions itself, which makes them cheaper and faster, and then posts transaction data or proofs back to the base chain for security.
Common types
- Optimistic rollups assume transactions are valid unless challenged. Withdrawals to the base chain through the official bridge include a challenge period, often around a week. Arbitrum-based chains work this way.
- ZK rollups post cryptographic proofs that transactions are valid.
Robinhood Chain
Robinhood Chain is an Ethereum layer 2 built with Arbitrum technology. Like most layer 2s today, it relies on a sequencer to order transactions. It uses first-come, first-served ordering. See What is Robinhood Chain? for details.
Educational content only. Not financial advice.