React Suspense allows us to let components wait before rendering. At the moment, React Suspense only allows us to dynamically load components with React.lazy. In the future, Suspense will support other use cases, such as data fetching.

React.lazy is another form of performance optimization. It lets us load a component dynamically in order to reduce the bundle size. Sometimes we want to avoid loading all of the components during the initial render, and only request certain components when they are needed.

For example, if our blog has a member area, we only need to load it after the user has logged in. Doing this will reduce the bundle size for guests who only visit our blog to read blog posts. To learn about React Suspense, we are going to lazily load the Logout component in our blog app.