Comprendre le déploiement

You built something amazing on your laptop. But right now, only you can see it. To share it with the world, you need to deploy it.

Deploying means putting your app on a computer that's always on and connected to the internet — a server — so anyone with a link can use it. That link is your app's address: a live URL like your-app.vercel.app.

In this lesson you'll learn what deployment really is, in plain language, so the rest of this course feels easy.

When you run your app on your own machine, it's local. The address usually looks like http://localhost:3000. That word localhost means "this very computer" — nobody else can open it.

A live app runs on a host that's reachable from anywhere. Same code, different home.

• Local: only on your laptop, for building and testing.
• Live: on the internet, for real users.

Deploying is simply moving your app from local to live.

When you deploy, three things happen behind the scenes. Don't worry — modern tools and AI handle them for you.

• Upload: your code is sent to the host.
• Build: the host turns your source files into a fast, optimized version.
• Serve: the host runs it and gives you a URL.

You'll hear the word build a lot. It just means "prepare my app to run for real." The AI knows this; you can simply ask it to explain any step.

Apps have two sides, and they can be hosted differently.

• Frontend: what users see — pages, buttons, styles. Often just static files.
• Backend: the logic and data behind the scenes — logins, databases, APIs.

A simple website might be frontend only, which is the easiest thing to deploy. A full app needs a host that runs backend code too. Tools like Vercel and Netlify can handle both, which is why beginners love them.

You don't need to rent a server or learn system administration anymore. Modern platforms make deploying almost magical:

• Vercel — loved for frontend and full-stack apps; one click from your code.
• Netlify — great for sites and simple apps.
• Replit — build and host right in the browser.

These are called Platform-as-a-Service (PaaS). They take your code and give you a live URL — no servers to babysit.

The fastest way to understand deployment for your app is to ask. Vibe coding means you don't memorize — you describe your situation and let AI guide you.

Try a prompt like the one below in Cursor, Claude Code, or any AI chat. Paste in details about your project so the answer fits you.

After deploying, you get a public web address. On Vercel it might be my-todo-app.vercel.app; on Netlify, my-todo-app.netlify.app.

Anyone can open that link on any device. Later you can attach your own domain (like mytodo.com) — we cover that in a later lesson.

Here's a tiny snippet of JavaScript that reads the address the browser is currently on. On a live app, this would print your real URL.

Deploying isn't a one-time event. Every time you improve your app, you redeploy to push the new version live.

The best modern hosts do this automatically: when you save your changes to Git (your project's history) and push, the host detects it and rebuilds. This is called continuous deployment.

That's why version control and deploying go hand in hand. The takeaway: once set up, shipping an update is as easy as saving your work.

Good news for builders: nearly all these platforms have free tiers generous enough for learning, side projects, and even small real apps.

• Free hosting for personal projects.
• A free .vercel.app or .netlify.app link.
• Automatic HTTPS (the secure padlock) included.

You only pay when you grow — lots of traffic, advanced features, or a team. For your first launches, $0 is the norm.

Hold this simple picture in your head for the whole course:

• You build on your laptop (local).
• You deploy to a host (Vercel, Netlify, Replit).
• The host gives you a live URL.
• You redeploy whenever you make changes.

That's the entire deployment loop. Everything else — domains, environments, settings — is just polish on top of this core idea.

Not sure which host fits your project? Describe what you built and let AI recommend one. This is a perfect vibe-coding move.

Try the prompt below. The more you tell the AI about your app, the better its recommendation.

You've got the deployment mental model down. Let's check it.

You now understand the foundation of shipping:

• Local = only on your machine; live = on the internet.
• Deploying does three things: upload, build, serve.
• Modern hosts (Vercel, Netlify, Replit) hand you a live URL with a free tier.
• Deploys are repeatable — redeploy to ship updates.
• When in doubt, ask AI to recommend a host and walk you through it.

Next up: actually pushing your app to Vercel or Netlify, step by step.