What is a web app? PWAs, single page applications and hybrid apps explained

What is a web application?

A web application is a program that lives on a server and is used through a browser. The screen you see is built with HTML, CSS and JavaScript; the data and logic sit on the server. Nothing needs to be downloaded from an app store, it works on any device with a browser, and everyone always uses the latest version.

Examples of web based applications: webmail, online stores with accounts, internet banking, Google Docs and Sheets, project management tools, CRM systems, online appointment booking and school or staff portals.

What is the difference between a website and a web app?

A website mainly gives information: pages you read. A web app lets you do something: log in, enter data, book, buy, manage records. Many sites are both, such as a company website with a customer login area. The line is about interaction, not technology.

What is a PWA (progressive web app)?

A progressive web app is a web app built so that it behaves like a native app:

• It can be installed to the home screen or desktop from the browser.
• It can work offline or on weak connections, using a service worker that caches files.
• It can send push notifications on supported devices.
• It opens in its own window without the browser's address bar.

Twitter's mobile site, Starbucks' ordering app and Microsoft's Outlook web app are well-known PWAs.

What is Outlook PWA?

Outlook PWA is the installable version of Outlook on the web. When you open Outlook in Edge or Chrome, the browser offers to install it as an app. It then opens in its own window, shows in your taskbar or dock and supports notifications, while still running the web version of Outlook underneath.

What does PWA stand for?

PWA stands for progressive web app. "Progressive" means the app works in any browser and adds app-like features, such as installation and offline use, where the device supports them.

What is a single page application?

A single page application (SPA) loads one HTML page and then updates the content with JavaScript as you click, instead of loading a new page from the server each time. Gmail and Google Maps work this way. SPAs feel fast once loaded and are usually built with frameworks such as React, Angular or Vue.

SPAs and SEO: search engines can read SPAs, but content that only appears after JavaScript runs may be indexed late or missed. Public pages that need to rank should be server-rendered or pre-rendered. See technical SEO.

What are hybrid apps?

A hybrid app is built with web technologies and wrapped in a native shell so it can be published in app stores, using tools such as Ionic, Capacitor or Cordova. Frameworks such as React Native and Flutter are related but produce native interface components, so they are usually called cross-platform rather than hybrid.

Web app, PWA, hybrid or native: which should a business choose?

• Web app for internal tools, portals, booking and anything used mainly on a computer or occasionally on a phone.
• PWA when customers will use it often on phones and you want installation and notifications without app store costs.
• Hybrid or cross-platform when you need app store presence with one codebase.
• Native when you need heavy device features, top performance or offline work for long periods.

Most small and mid-sized businesses start with a web app or PWA: one build, every device, no store approvals.

What does a web app cost?

At Sitesetu one custom web app, within a published scope, is part of the ₹19,999$399 Pro package together with a website. See web app development.