React Server Components

RSC render on the server and send a serialized tree to the client, minimizing client JS.

Core idea

• Components run on the server, not the browser.
• Output is a serialized tree merged with Client Components.
• No DOM, state, effect hooks, or browser APIs.

Why App Router depends on RSC

• Move data fetching and heavy logic to the server.
• Smaller client bundle, less hydration.
• Enables streaming and partial rendering via Suspense.
• Supports Server Actions without HTTP endpoints.

What RSC enable

• Secure access to DB and secrets.
• Caching at fetch and route levels.
• Fast UI delivery with HTML + RSC payload.

When Client Components are needed

• Interactivity, state, effects, DOM APIs, client-only libraries.