<Fragment>, alternatively written as <>...</>, lets you group multiple JSX nodes together.
<Profiler> lets you measure the rendering performance of a React tree programmatically.
<Suspense> lets you display a fallback while the child components are loading.
<StrictMode> enables extra development-only checks that help you find bugs early.
<DeferredValue> While primarily used as a hook (useDeferredValue), the concept is built into the React engine to help you defer updating a non-urgent part of the UI. This is often used to keep an input field responsive while a heavy list filters in the background.
Metadata Components React 19 introduced built-in support for rendering document metadata tags anywhere in your component tree. React will automatically hoist these to the <head> of the HTML document.