Next.js

What Next.js is

Next.js is Vercel’s React framework for full-stack web applications. It extends React with routing, rendering modes, server-side features, data fetching, build tooling, and a deployment model closely connected to Vercel but not limited to it.

It became central to the React ecosystem because it provides the application frame React does not provide alone: file-based routing, SSR/SSG, server rendering, API routes/server actions, image/font optimization, bundling, and production conventions.

What is inside and how it is used

export default function Page() {
  return (
    <main>
      <h1>Hello from Next.js</h1>
      <p>This page is rendered through the app router.</p>
    </main>
  );
}

The repository contains framework code, compiler/build tooling, examples, tests, docs, and contributor workflow. In practice, it powers sites, SaaS apps, dashboards, docs, e-commerce, and content-heavy products.

Strengths and limits

Its strength is an integrated path from component to production. Its limit is model complexity: server/client boundaries, caching, routing, deployment target, and React/Next versions need careful understanding. For a simple SPA, it can be heavier than needed.