Next.js 14: Server Components and App Router

Next.js 14 introduced significant improvements with the App Router and Server Components. These features enable better performance and a more intuitive development experience.

Server Components vs Client Components

Understanding when to use each:

Server Components (default):

• Fetch data on the server
• Access backend resources directly
• Keep sensitive logic server-side
• Reduce client-side JavaScript

Client Components:

• Add interactivity with 'use client'
• Use browser APIs
• Manage client-side state

// Server Component (default)
async function Posts() {
    const posts = await fetchPosts();
    return <PostList posts={posts} />;
}

// Client Component
'use client';
function LikeButton() {
    const [liked, setLiked] = useState(false);
    return <button onClick={() => setLiked(!liked)}>Like</button>;
}

The New App Router

Key features of the App Router:

• File-based routing with app/ directory
• Nested layouts for shared UI
• Loading and error states built-in
• Parallel and intercepting routes

Optimization Tips

We'll also explore how to optimize your Next.js applications with streaming, partial prerendering, and smart caching strategies.