Glossary

Next.js · Reference cheat sheet

📋 Overview

Alphabetical glossary of Next.js terms spanning App Router, rendering, caching, and deployment.

🔧 Core concepts

Term	Definition
App Router	Routing system based on the `app/` directory and special files.
CSR	Client-side rendering in the browser after JS loads.
Dynamic segment	Folder like `[id]` that captures a URL parameter.
Edge runtime	Lightweight runtime for Middleware and some Route Handlers.
Hydration	Attaching client React to server-rendered HTML.
ISR	Incremental Static Regeneration — update static pages after deploy.
Layout	Persistent UI wrapper (`layout.tsx`) shared by child routes.
Middleware	Edge code that runs before a request is completed.
Partial Prerendering	Hybrid static shell + dynamic holes (version-dependent).
Prefetch	Loading a route in the background via `Link`.
Route Handler	`route.ts` exporting HTTP methods as an API endpoint.
Route group	`(name)` folder that organizes routes without affecting the URL.
RSC	React Server Component rendered on the server by default.
Soft navigation	Client transition without full document reload.
SSG	Static Site Generation at build time.
SSR	Server-Side Rendering on each request.
Streaming	Sending UI in chunks via Suspense / `loading.tsx`.
Turbopack	Rust-based bundler used in modern `next dev`.

💡 Examples

Dynamic segment mental model:

app/shop/[slug]/page.tsx  →  /shop/shoes

RSC vs client:

// Server (default)
export default async function Page() { /* fetch, await */ }

// Client
"use client";
export function Widget() { /* useState, onClick */ }

⚠️ Pitfalls

Glossaries drift — verify behavior against your installed Next.js major version.
“Static” vs “dynamic” depends on APIs used (cookies, headers, no-store), not folder names alone.

Glossary

Glossary

📋 Overview

🔧 Core concepts

💡 Examples

⚠️ Pitfalls

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