Explain React Server Components at a high level and how they differ from client components.

Server Components render on the server and send a serialized representation to the client without shipping their component code as client JS for that subtree. Client Components hydrate and can use state, effects, and browser APIs. In frameworks like Next.js App Router, the split is explicit via directives and boundaries.

Server Components can fetch sensitive or heavy data closer to the database and keep large dependencies off the client bundle. Interactive UI still belongs in Client Components; composition passes serializable props across the boundary.