It is documented in our [code splitting guide](/docs/code-splitting.html#reactlazy). Note that `lazy` components can be deep inside the `Suspense` tree -- it doesn't have to wrap every one of them. The best practice is to place `<Suspense>` where you want to see a loading indicator, but to use `lazy()` wherever you want to do code splitting.
> Note
>
>
> For content that is already shown to the user, switching back to a loading indicator can be disorienting. It is sometimes better to show the "old" UI while the new UI is being prepared. To do this, you can use the new transition APIs [`startTransition`](#starttransition) and [`useTransition`](/docs/hooks-reference.html#usetransition) to mark updates as transitions and avoid unexpected fallbacks.
#### `React.Suspense` in Server Side Rendering {#reactsuspense-in-server-side-rendering}
@ -375,7 +375,7 @@ During server side rendering Suspense Boundaries allow you to flush your applica
When a component suspends we schedule a low priority task to render the closest Suspense boundary's fallback. If the component unsuspends before we flush the fallback then we send down the actual content and throw away the fallback.
#### `React.Suspense` during hydration {#reactsuspense-during-hydration}
Suspense boundaries depend on their parent boundaries being hydrated before they can hydrate, but they can hydrate independently from sibling boundaries. Events on a boundary before its hydrated will cause the boundary to hydrate at
Suspense boundaries depend on their parent boundaries being hydrated before they can hydrate, but they can hydrate independently from sibling boundaries. Events on a boundary before its hydrated will cause the boundary to hydrate at
a higher priority than neighboring boundaries. [Read more](https://github.com/reactwg/react-18/discussions/130)
> Updates in a transition yield to more urgent updates such as clicks.
>
> Updates in a transitions will not show a fallback for re-suspended content, allowing the user to continue interacting while rendering the update.
> Updates in a transition will not show a fallback for re-suspended content, allowing the user to continue interacting while rendering the update.
>
> `React.startTransition` does not provide an `isPending` flag. To track the pending status of a transition see [`React.useTransition`](/docs/hooks-reference.html#usetransition).