Why this question deserves more than a quick answer

Site, Headless site, web app, mobile app, PWA. Five words used every day by agencies, vendors and procurement — and which actually describe five very different technical and budgetary realities. Mixing up the first two is rarely a problem. Mixing up a "web app" and a "big site" can drift a budget from €4,000 to €40,000.

This article lays out clear definitions, gives concrete markers for each family, and illustrates with examples.

The five families, without jargon

1. The classic brochure site

A site that presents: your activity, your services, your team, your content. The visitor consumes information — reads, watches, clicks, and may fill out a contact form.

On the technical side, the classic WordPress site remains relevant: a theme, a few plugins, the Gutenberg editor for content. The visitor receives an HTML page generated on demand by the PHP server.

Examples: a lawyer's website, a non-profit site, the site of an industrial SME.

2. The Headless site

Still a site that presents, but whose architecture is split in two: a back-office (WordPress, in our case) that manages content, and a front end (Next.js) that displays it. Performance perceived by the visitor is on a different scale: pre-generated pages, near-instant load, Lighthouse score > 90.

It's still a site, not a web app — the visitor doesn't create an account, doesn't enter business data, doesn't trigger applicative logic. They consume content, just faster.

Examples: a high-traffic media site, an editorial platform, an institutional site with structured content and an active blog.

3. The web app

Here we cross over. The visitor is no longer just a spectator: they create an account, enter data, interact with other users, trigger business processes. The site becomes a tool.

A web app has:

  • A dedicated database to store business data (users, products, transactions, etc.)
  • An authentication system (accounts, sessions, roles)
  • Its own business logic (calculations, workflows, validations)
  • A custom admin interface to drive it all

Stack-wise, we leave WordPress: Next.js + serverless PostgreSQL database + autonomous admin designed for the project.

Examples: a B2B marketplace (Panorama Pub), an internal management tool, a quote configurator, a complex calculator, a member area with personalized content.

4. The mobile application (PWA)

This is a web app designed for mobile and installable on the phone's home screen — without going through the App Store or Play Store. The visitor taps "Add to home screen" from their browser, and the app installs like a real app.

A PWA can access geolocation, work offline, receive notifications. It's technically a website, but the user experience feels like a native app.

Examples: a mobile treasure hunt (Hermitage), a field tool for technicians, an installable tourist guide.

5. The native mobile application

Built with Swift (iOS) or Kotlin (Android), published on the Apple and Google stores, downloaded and installed. It has access to all phone features: advanced camera, sensors, integrated payment, complex push notifications, deep OS integration.

Cost-wise, we change orders of magnitude: specific development per platform, store validation (a few days to several weeks), maintenance across 2 distinct environments.

Example: a mobile bank, a social network like TikTok, a mobile video game.

Next Impact doesn't build native apps. For 95% of mobile projects, a well-designed PWA is enough and costs three to ten times less. When the need falls outside that scope, I refer to a specialized mobile studio.

The 5 markers to recognize a web app

If any of these 5 markers appears in your spec, you're describing a web app — not a site:

  1. User accounts with personal data to store
  2. Business logic: calculations, workflows, complex validations
  3. Structured data specific to the business (catalogues, transactions, appointments, etc.)
  4. Real-time interaction between users (chat, notifications, live updates)
  5. Strong personalization of the interface based on the logged-in user

Conversely, if your project boils down to "presenting content, highlighting an activity, collecting leads through a contact form" — you're on a site, not a web app.

Management autonomy: a myth to dispel

A common fear: "If I leave WordPress for a custom web app, I lose the autonomy to edit my own content."

That's wrong — at least when the app is well designed. Every web app delivered by Next Impact comes with a custom admin interface, built for the project's business logic:

  • You manage your content, your data, your users
  • You don't need a developer for everyday operations
  • The interface is designed for your team, not for a generic audience

It's the equivalent of the WordPress admin, but for an applicative logic specific to your project instead of a generic editorial logic.

Summary

| Family | The visitor | Typical stack | Indicative budget | |---|---|---|---| | Brochure site | Consumes | Classic WordPress | €2,250 - €6,000 | | Headless site | Consumes (fast) | WordPress + Next.js | €4,000 - €15,000 | | Web app | Creates, enters, interacts | Next.js + PostgreSQL | €15,000 - €80,000+ | | Mobile PWA | Same + field/mobile usage | Next.js + PWA | On quote | | Native app | Same + OS integration | Swift / Kotlin | €50,000+ |

Going further

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