When Should You Use React Versus Single Page Applications?

When is it good to use react verse single page applications in general? We need to talk about SPA's, he says. A single page application makes sense because your user interaction isn't based on navigating between content so if you don't  if your primary interactions are based more on lots of little bits of state here and there that combine with a bunch of logic to produce some output then I'd say you're looking at a single page application. He explains how React can add complication make it harder to optimize for search engines or get good performance.