Update docs

- remove implementation details
- mention `identifierPrefix`

Author: ciffelia

packages/dev/docs/pages/react-aria/ssr.mdx

@@ -44,16 +44,21 @@ When strict mode is enabled on React 16 or 17, it generates different IDs betwee
 
 ## Automatic ID Generation
 
+### React 18
+
 If you are using React 18, React Aria uses [React.useId](https://reactjs.org/docs/hooks-reference.html#useid) to generate unique IDs that are stable across the client and server.
 
+If your React app have multiple roots, you need to configure `identifierPrefix` option on `hydrateRoot` and `ReactDOMServer` to prevent collisions. For more information, please see the documentation of [React.useId](https://reactjs.org/docs/hooks-reference.html#useid).
+
+### React 16 and 17
+
 If you are using React 16 or 17, React Aria tries to generate consistent IDs by itself. In this case, when using SSR, only a single copy of React Aria can be on the page at a time, and React StrictMode cannot be supported.
 
-If you use React Aria’s [useId](useId.html) hook in your own components, `SSRProvider` will ensure the ids are consistent when server rendered. No additional changes in each component are required to enable
-SSR support.
+You may use React Aria’s [useId](useId.html) hook in your own components. `SSRProvider` will ensure the ids are consistent when server rendered. No additional changes in each component are required to enable SSR support.
 
 ## SSR specific rendering
 
-You can also use the [useIsSSR](useIsSSR.html) hook in your own components to determine whether they are running in an SSR context. This hook returns `true` both during server rendering and hydration, but updates immediately to `false` after hydration. You can use this to delay browser-specific code like media queries and feature detection until after the client has hydrated.
+You can use the [useIsSSR](useIsSSR.html) hook in your own components to determine whether they are running in an SSR context. This hook returns `true` both during server rendering and hydration, but updates immediately to `false` after hydration. You can use this to delay browser-specific code like media queries and feature detection until after the client has hydrated.
 
 ```tsx
 import {useIsSSR} from '@react-aria/ssr';

packages/dev/docs/pages/react-spectrum/ssr.mdx

@@ -45,7 +45,7 @@ Wrapping your application in an `SSRProvider` ensures that the HTML generated on
 Note that `SSRProvider` doesn't support [strict mode](https://reactjs.org/docs/strict-mode.html) on React 16 and 17.
 When strict mode is enabled on React 16 or 17, it generates different IDs between server and client. That results in hydration errors.
 
-When using SSR, only a single copy of React Spectrum can be on the page at a time. This is in contrast to client-side rendering, where multiple copies from different parts of an app can coexist. Internally, many components rely on auto-generated ids to link related elements via ARIA attributes. When server side rendering, these ids need to be consistent so they match between the server and client, and this would not be possible with multiple copies of React Spectrum.
+When using SSR, only a single copy of React Spectrum can be on the page at a time. If you are using React 18, you may configure `identifierPrefix` option on `hydrateRoot` and `ReactDOMServer` to bypass this restriction. For more information, please see the documentation of [React.useId](https://reactjs.org/docs/hooks-reference.html#useid).
 
 Media queries and DOM feature detection cannot be performed on the server because they depend on specific browser parameters that aren’t sent as part of the request. In cases where these affect the rendering of a particular component, this check is delayed until just after hydration is completed. This ensures that the rendering is consistent between the server and hydrated DOM, but updated immediately after the page becomes interactive.