Understanding React Server Components vs. Client Components

React Server Components (RSCs) represent one of the biggest shifts in React's architecture. The primary motivation is to combat the ever-growing JavaScript bundle sizes and complex data-fetching waterfalls that can slow down our applications. By moving components to the server, we can send a much lighter, non-interactive HTML payload to the client, resulting in a significantly faster initial page load. A Server Component runs exclusively on the server. It can fetch data directly, access the backend filesystem, and it never sends its JavaScript to the client. This makes it perfect for static parts of your UI like text, images, and data displays. In contrast, a Client Component is the traditional React component we all know. It runs on the client, can use state (useState) and effects (useEffect), and handles all user interactivity. You explicitly opt-in to a Client Component by placing a "use client" directive at the top of the file. The true power lies in how they work together. The recommended approach is to build your application with Server Components by default and only use Client Components for the interactive "islands" within your UI. This hybrid model gives you the best of both worlds: the performance benefits of server-side rendering and the rich interactivity of a client-side application.