Refreshing Server Component Data Without a Full Page Reload

Calling router.refresh() (or revalidatePath/revalidateTag inside a Server Action) triggers the server to re-render the affected route segment and stream the updated HTML to the client, since Server Components fetch data at render time and have no client-side refetch mechanism of their own.

Wrapping the Server Component in useMemo causes it to automatically re-invoke its data fetch whenever any client state changes anywhere in the tree.

Server Components automatically poll their original data source every few seconds without any explicit refresh call.

Attaching an onUpdate prop to a Server Component causes React to re-execute it in place, similar to a client-side effect.