Reanimated V2 is an animation library for React Native that allows you to create complex, high-performance animations and transitions in mobile apps. It uses a declarative syntax and a node-based architecture that allows you to compose animations in an intuitive and scalable way. Reanimated V2 also provides a number of hooks and utilities to facilitate animation state management and user interactivity control. Overall, Reanimated V2 is a powerful tool for creating smooth, high-quality animations in mobile applications.