What is a cryptocurrency and a blockchain network that acts as a Layer 2 scaling solution for the Ethereum network.

Optimism aims to make Ethereum transactions faster and more cost-effective by reducing transaction fees and delays that may occur on the main Ethereum network.

Optimism uses "Optimistic Rollups" technology that allows transactions to be executed off the main Ethereum chain, which are then aggregated and verified on Ethereum, maintaining the security of Ethereum.

The OP token is used to pay transaction fees and participate in the governance of the Optimism ecosystem, allowing its holders to vote on important decisions related to the protocol and fund allocation.