Gatsby and Next.js are both site frameworks powered by React. They can both be used for static and dynamic sites with different conventions and features around

Gatsby and Next.js are both site frameworks powered by React. They can both be used for static and dynamic sites with different conventions and features around routing, data management, and general app architecture. Both are "hip" and will likely remain as the top 2 javascript based site frameworks for now, although whether you need either of them is an entirely different question.