Next.js Introduction & Setup

▲ Next.js 15+ (App Router) 🟢 Chapter 1 of 43 📂 Phase 1: Next.js Introduction 📅 2026 Edition

📌 Covered in this chapter: Next.js ante enti? · React vs Next.js · Main Features · Full-Stack Framework · Rendering Models (SSR/SSG/ISR/CSR/RSC) · Use Cases & Limitations

Next.js ante enti, Vercel enduku create chesindi, React tho compare chesthe em extra istundi ane deep-dive introduction. Ee chapter lo core rendering models (SSR, SSG, ISR, CSR, React Server Components), full-stack framework capabilities, and mee first Next.js page create cheyadam nerchukuntaru.

1Next.js Ante Enti? Origins, Purpose & Why It Exists

Next.js is an open-source React framework, built and maintained by Vercel (formerly Zeit), first released in 2016 by Guillermo Rauch's team. React itself kevalam oka UI library — components, JSX, state ela manage cheyalo cheputundi, kani routing ela cheyalo, server meedha rendering ela cheyalo, files ela organize cheyalo React cheppadu. Deenini "batteries not included" problem antaru.

Next.js exact ga aa gap ni fill chesthundi — routing, rendering strategies (SSR/SSG/ISR), data fetching, backend API routes, image/font optimization, and production deployment — anni ఒకే framework లో combine chesi istundi, so developers "React + 10 other libraries" wire cheyakunda, direct ga production-ready apps build cheyachu.

Key Characteristics of Next.js:

React Meeda Built: Next.js React component model, JSX, hooks anni same ga use chestundi — kotha language nerchukovalsina pani ledu.
Full-Stack Framework: Frontend UI + backend Route Handlers + database queries anni oke codebase lo, oke project lo rayochu.
File-System Based Routing: app/ folder lopala files/folders create chesthe, avi automatic ga URL routes ga map avthayi — separate router library avasaram ledu.
Flexible Rendering: Prathi page ki independent ga decide cheyachu — Server-side render cheyala, static ga build time lo generate cheyala, leda client meedha render cheyala ani.

Next.js create cheyadaniki official CLI tool create-next-app use chesthe, ready-made project structure, TypeScript, ESLint, Tailwind CSS anni pre-configured ga vasthayi:

💻 Example 1: Creating a New Next.js Project

Terminal ▶ Run in Compiler

npx create-next-app@latest my-next-app
cd my-next-app
npm run dev

🔍 Command-by-Command Breakdown:

npx create-next-app@latest: Latest Next.js version ni download chesi, interactive prompts (TypeScript? ESLint? App Router? Tailwind?) adigi, complete boilerplate project generate chestundi.
cd my-next-app: Newly created project folder loki navigate chestundi.
npm run dev: Local development server ni http://localhost:3000 meedha start chestundi, with hot-reload enabled.

2React vs Next.js — Key Differences

Chala mandi beginners "React vs Next.js" ani confuse avutaru — kani ivi competing technologies kaadu. Next.js is built on top of React; Next.js ni use cheyalante mundu React ardham avvali. Kింద table lo main differences chudandi:

Feature	Plain React (Vite/CRA)	Next.js
Routing	Manual — react-router-dom lanti library install cheyali	Built-in file-system routing (`app/` folder)
Rendering	Client-side rendering (CSR) only	SSR, SSG, ISR, CSR — anni support chestundi
Backend/API	Separate backend server avasaram (Express, Django, etc.)	Built-in Route Handlers — same project lo API endpoints
SEO	Weak by default (empty HTML shell + JS)	Strong — server meedha pre-rendered HTML
Image/Font Optimization	Manual configuration avasaram	Built-in `next/image`, `next/font`
Deployment	Static hosting (Netlify, S3, etc.)	Vercel, Docker, or any Node.js server

Short lo cheppalante: plain React chala flexible, kani manual setup ekkuva; Next.js opinionated structure isthundi, kani production features anni ready-made ga vastayi.

3Your First Next.js Page (app/page.tsx)

Next.js App Router lo, app/ folder lopala unna prathi page.tsx file, automatic ga oka public URL route avthundi. Root level app/page.tsx exact ga / (home page) ni represent chestundi:

💻 Example 2: A Minimal Home Page Component

app/page.tsx ▶ Run in Compiler

export default function Home() {
  return (
    <main>
      <h1>Welcome to My Next.js App 🚀</h1>
      <p>This page is server-rendered by default.</p>
    </main>
  );
}

🔍 Line-by-Line Code Breakdown:

export default function Home(): Every route ki oka default-exported React component undali — deeni peru edaina kavachu, kani file location URL decide chestundi, function name kadhu.
return (...): JSX markup return chestundi — idi ordinary React component laane pani chestundi.
Extra imports, wrapper HTML, <html>/<body> tags avasaram ledu — avi layout.tsx lo already define chesi untaru.

Browser URL: http://localhost:3000/

4Core Rendering Models: SSR, SSG, ISR, CSR & RSC

Next.js main superpower — prathi page ki independent ga rendering strategy choose cheyagalగడం. Ee 5 models ardham cheskovadam chala important:

SSR (Server-Side Rendering): Prathi request ki fresh ga server meedha HTML generate avuthundi — real-time data (dashboards, user-specific pages) ki best.
SSG (Static Site Generation): Build time lo ఒక్కసారి HTML generate chesi, CDN meedha cache chesthundi — blogs, marketing pages ki super fast.
ISR (Incremental Static Regeneration): SSG లాగానే, kani specific time interval tarvatha background lo automatic ga re-generate avuthundi — e-commerce product pages ki ideal.
CSR (Client-Side Rendering): Browser లోనే JavaScript run chesi content render chestundi — interactive dashboards, authenticated apps ki common.
RSC (React Server Components): Next.js App Router default — components server meedha render అయ్యి, zero extra JavaScript browser ki పంపిస్తాయి (unless "use client" pెడితే).

┌──────────────────────────┐ │ Browser Request (/blog) │ └─────────────┬────────────┘ │ ▼ [Next.js Server decides rendering strategy] ┌──────────────────────────┐ │ Server Component Tree │ (Default: rendered on server, zero client JS) │ + Data Fetching (DB) │ └─────────────┬────────────┘ │ ▼ [Client Components hydrate only where needed] ┌──────────────────────────┐ │ "use client" Components │ (Interactive: buttons, forms, state) └─────────────┬────────────┘ │ ▼ ┌──────────────────────────┐ │ Final HTML + minimal │ │ JS sent to Browser │ └──────────────────────────┘

Key takeaway: Next.js App Router lo, default ga anni components Server Components — interactivity (onClick, useState) kavali ante matrame top lo "use client" add chestaru.

5Full-Stack Capabilities, Use Cases & Limitations

Next.js kevalam frontend framework kaadu — Route Handlers use chesi, same project lo backend API endpoints kuda create cheyachu, database (Prisma, PostgreSQL, MongoDB) tho direct ga connect cheyachu. Deeni valla separate backend server (Express/Django) avasaram ledu, chinna-madhyathara projects ki.

Common Use Cases:

Marketing websites & landing pages (fast SSG loading)
E-commerce storefronts (ISR + dynamic product pages)
SaaS dashboards & admin panels (SSR + auth)
Full-stack applications with database-backed APIs
Blogs & documentation sites (Markdown + SSG)

Limitations to Keep in Mind:

Learning curve ekkuva — App Router, Server/Client component boundary ardham cheskovadam beginners ki confusing avvachu.
Hosting flexibility — full features (Image Optimization, ISR) కోసం Vercel-style platform best; plain static hosting meedha konni features limited avthayi.
Simple static sites కోసం (avoiding SSR complexity), plain React or plain HTML/CSS sometimes overkill-free alternative avvachu.

⚠️ Common Developer Pitfall: useState in a Server Component

App Router default ga anni components Server Components. Server Component lo direct ga useState or onClick vాడితే, "You're importing a component that needs useState — this React hook only works in a Client Component" ane error వస్తుంది. Interactivity avasaram unna component top lo "use client"; directive add cheyali.

💻 Hands-on Interactive Practice Challenge

Create a new page at app/about/page.tsx that returns a simple "About Us" heading and a short paragraph, then link to it from the home page using the Link component.

app/about/page.tsx ▶ Run in Compiler

export default function About() {
  return (
    <main>
      <h1>About Us</h1>
      <p>We build fast, full-stack apps with Next.js.</p>
    </main>
  );
}

Run This Challenge in Online Node.js IDE →

❓ Frequently Asked Questions (FAQ)

Q Next.js use chesthe React marchipovala?

Ledu. Next.js React meeda build chesina framework — anni React concepts (components, JSX, props, state, hooks) same ga work chestayi. Next.js kevalam routing, rendering, data fetching, and backend features add chestundi.

Q Next.js free ah, paid ah?

Next.js framework itself completely free and open-source (MIT License), Vercel maintain chestundi. Deployment kosam Vercel platform lo free tier tho paatu paid tiers kuda unnayi; mee project ni Netlify, AWS, Docker vంటివి ఇతర platforms meedha kuda deploy cheyachu.

Q React nerchukokunda direct ga Next.js nerchukovacha?

Technically start cheyochu, kani recommended kadhu. Components, JSX, props, state, hooks lanti React fundamentals ముందు nerchukunte, Next.js concepts (Server Components, App Router, Server Actions) chala easy ga అర్థం avthayi.

Written by Our Compiler Technical Editorial Team
Reviewed for accuracy & tested on Next.js 15+ (App Router) · Last updated August 2026