The Unlike traditional Server-Side Rendering<\/a> which returns a complete HTML<\/a> document, an The _rsc<\/code> identifier is a specialized query parameter and file extension suffix used primarily within the Next.js<\/a> framework to manage the delivery of React Server Components<\/a> (RSC). In modern web architectures utilizing the App Router<\/a>, _rsc<\/code> requests are triggered during client-side navigation to fetch the serialized data required to render server-side logic without performing a full browser refresh.<\/p>_rsc<\/code> request returns a stream of serialized data. This payload contains the instructions necessary for the React Flight Runtime<\/a> to reconstruct the Virtual DOM<\/a> tree on the client. According to the Next.js Documentation<\/a>, this approach enables Partial Rendering<\/a>, where only the changed segments of a layout are updated, significantly improving Web Performance<\/a>.<\/p>_rsc<\/code> payload includes several key pieces of information: the rendered output of server components, placeholders for Client Components<\/a> (known as client references), and any props passed from the server to the client. This allows for a seamless Hydration<\/a> process where the client-side state is preserved even as new server-rendered content is integrated into the DOM<\/a>. As noted in the React Labs update<\/a>, this architecture helps reduce the JavaScript<\/a> bundle size by keeping heavy dependencies on the server.<\/p>