Optimism is a Layer 2 scaling solution for Ethereum that aims to improve the scalability and usability of the Ethereum network. It is built using Optimistic Rollups, a technology that allows for fast and inexpensive transactions on top of the Ethereum network.

Optimistic Rollups work by aggregating multiple transactions into a single batch, which is then verified off-chain by a small group of validators. This reduces the computational burden on the Ethereum network, allowing for faster and cheaper transactions. In addition, Optimism also supports Ethereum-compatible smart contracts, allowing developers to deploy and run decentralized applications on top of the Optimism network.

One of the key benefits of Optimism is that it allows users to interact with Ethereum without having to pay high gas fees or wait for long confirmation times. This makes it easier and more affordable for users to participate in DeFi protocols, NFT marketplaces, and other Ethereum-based applications.

Overall, Optimism is an important project that is helping to improve the scalability and usability of Ethereum, making it more accessible to a wider range of users and use cases.