The Power of Server Components in Next.js 13+

Next.js 13 introduced a paradigm shift with React Server Components. This new architecture allows developers to build applications that combine the rich interactivity of client-side apps with the performance benefits of traditional server rendering.

What Are Server Components?

Server Components allow you to write UI that can be rendered and optionally cached on the server. They:

• Reduce the client-side JavaScript bundle size
• Enable faster page loads and improved SEO
• Allow direct access to backend resources
• Hide sensitive code and data from the client

Server vs. Client Components

In Next.js, components inside the app directory are Server Components by default. This means they render on the server and don't require client-side JavaScript.

Here's a simple example of a Server Component:

async function DatabaseData() {
  const data = await db.query("SELECT * FROM posts");

  return (
    <ul>
      {data.map((post) => (
        <li key={post.id}>{post.title}</li>
      ))}
    </ul>
  );
}

Notice how we can directly query the database without API routes!

When to Use Client Components

You'll need Client Components when you want to:

• Use interactive features (useState, useEffect, event handlers)
• Use browser-only APIs
• Use React Class components

To mark a component as a Client Component, add the "use client" directive at the top of the file:

"use client";

import { useState } from "react";

export default function Counter() {
  const [count, setCount] = useState(0);

  return (
    <div>
      <p>Count: {count}</p>
      <button onClick={() => setCount(count + 1)}>Increment</button>
    </div>
  );
}

Best Practices

• Push client components to the leaves of your component tree
• Pass data from Server Components to Client Components as props
• Use Suspense boundaries for asynchronous operations

The combination of Server and Client Components offers the best of both worlds - server-side performance with client-side interactivity.