Interactive Audio Learning Platform

Server-Side Rendering is a technique where React components are rendered on the server before being sent to the browser. This means the HTML is generated on the server for each request. SSR improves SEO because search engines can crawl the fully rendered HTML. It also provides faster initial page loads since users see content immediately, but subsequent navigation might be slower as each page requires server processing. Next.js makes SSR easy with getServerSideProps function.

Static Site Generation pre-renders pages at build time, creating static HTML files that can be served by a CDN. This is the fastest rendering method since pages are already built and ready to serve. SSG is perfect for content that doesn't change frequently like blogs, documentation, or marketing pages. Next.js generates static pages automatically for pages without dynamic data, and you can use getStaticProps for pages that need data at build time.

Client-Side Rendering means React runs in the browser and builds the page dynamically using JavaScript. The server sends a minimal HTML file with JavaScript bundles, and React takes over to render the page. CSR provides rich interactivity and smooth navigation between pages. However, it requires JavaScript to work and has slower initial loads. It's ideal for complex applications with lots of user interactions like dashboards or social media platforms.

Incremental Static Regeneration combines the benefits of SSG and SSR. Pages are statically generated at build time, but can be regenerated in the background when new requests come in. This allows you to have static performance with dynamic content. ISR is perfect for e-commerce sites, news sites, or any content that updates periodically. You can revalidate pages on-demand or set a time interval for automatic regeneration.

The App Router is Next.js 13+'s new routing system built on React Server Components. It introduces a file-system based router where folders define routes and special files like page.js, layout.js, and loading.js have specific purposes. The App Router enables better performance through server components, improved developer experience with co-location, and advanced features like nested layouts and streaming. It's the recommended way to build new Next.js applications.

React Server Components are a new type of component that runs only on the server. They don't ship JavaScript to the client, reducing bundle size. Server Components can directly access databases, file systems, or other server-only resources. They're perfect for components that don't need interactivity. Client Components are marked with 'use client' directive and run in the browser for interactive features. This hybrid approach optimizes both performance and functionality.

Hydration is the process where React takes over static HTML generated on the server and makes it interactive on the client. After the browser receives the server-rendered HTML, React downloads the JavaScript bundle and 'hydrates' the page by attaching event listeners and initializing component state. This process must match exactly between server and client to avoid hydration mismatches. Proper hydration ensures a smooth transition from static content to interactive application.

Code splitting is the practice of breaking your JavaScript bundle into smaller chunks that are loaded on-demand. Next.js automatically splits your code by pages and shared modules. Dynamic imports allow you to load components only when needed, reducing initial bundle size. This improves performance by loading only the necessary code for each page. Webpack's optimization ensures common code is shared between pages to avoid duplication.

Next.js build process involves several steps: TypeScript compilation, React JSX transformation, CSS processing, bundling with Webpack, and optimization. During development, Next.js uses fast refresh for instant updates. In production builds, code is minified, optimized, and split into chunks. The build process also handles static asset optimization, image optimization, and font optimization. Understanding this process helps debug issues and optimize performance.

Edge Runtime is a lightweight JavaScript runtime optimized for the edge. It's based on Web APIs rather than Node.js APIs, making it faster to start and more secure. Edge functions run closer to users geographically, reducing latency. They're perfect for middleware, API routes with simple logic, and server components that need fast cold starts. The trade-off is limited API compatibility compared to Node.js runtime.

Middleware in Next.js runs before requests are completed, allowing you to modify responses, redirect users, or add headers. It runs on the Edge Runtime for fast execution. Middleware is perfect for authentication, A/B testing, feature flags, and request logging. It can access cookies, headers, and URL information to make decisions. Middleware runs on every request that matches your configuration, making it powerful for cross-cutting concerns.

API Routes allow you to build API endpoints as part of your Next.js application. Each file in the pages/api or app/api directory becomes an API endpoint. These run as serverless functions, scaling automatically based on demand. API routes support all HTTP methods and can handle complex logic, database operations, and external API calls. They're deployed as separate functions, ensuring your API scales independently from your frontend.