Daily React is a helper library for building Daily applications in React, providing hooks, components, and utilities to help developers build faster with less code. It was created based on the experience of developing Daily Prebuilt and supporting customers at scale, focusing on overcoming challenges such as client performance and browser quirks. The library offers best practices for managing state mutations, optimizing client performance, and working with WebRTC specifications. By using Daily React, developers can reduce their exposure to common pitfalls and breaking changes, improve the aesthetics of their code, and simplify the process of building excellent video and audio apps.