3 Different things. html, css & js are like raw materials, React is processing these raw materials, and a UI components or design systems are the result you get

3 Different things. html, css & js are like raw materials, React is processing these raw materials, and a UI components or design systems are the result you get if you mix the React process with manual labor. The're frameworks and design systems. A React UI framework refines or enhances the React process to build UI components or design systems. Bootstrap e.g. is 2 things in 1, it's a process/framework and design system that sits directly on top of html, css & js.