As more people access the Internet using web browsers, web browsers have to evolve their sophistication and complexity to adapt to the traditional programs people have been accustomed to, programs that are installed locally on the computers. For example, many people are accustomed to the Microsoft Outlook program that they find the interface for the online web version lackluster. How does Microsoft make the web version of Outlook, accessed with a web browser, to have the look and feel of the desktop version of Outlook? The compromise is to make the web version a progressive web app.
PWAs are installed using the offline cache of a device's web browser. This is akin to Java applets that have been fallen out of favor because they require the Java virtual machine installed first on the device. PWAs only need a modern web browser to act like this virtual machine.
When you use a Chromebook, the only program on it is a glorified version of Google Chrome. This is where PWAs shine. You can use traditional programs as PWAs to get better performance. One such program is Zoom. Running Zoom on a web browser is slow and buggy because it has to interface with the computer's microphone, camera, and speaker. As a PWA, Zoom works better at these tasks.
https://learn.microsoft.com/en-us/microsoft-edge/progressive-web-apps-chromium
The first thing you notice when running the Outlook PWA is the removal of browser navigation buttons and the URL address bar. This makes the interface look like the desktop version of Outlook.
One side benefit is the offline nature of PWA can be used to cache an offline version of selected pages in a website so that you can browse these pages when the device is not connected to the Internet. This is basically the web crawler of the past. With PWA, the web crawler feature is built into the PWA so the website's administrator can control what pages can be cached using the PWA controls in the browser. This provides consistency of the caching across multiple web browsers. Imagine your daily routine is to visit a news website. You would casually access the various webpages while inside the PWA. Then you would hop on a bus to go to work. While you are on the bus, you can fire up this reading device and revisit the same web pages offline or only need to fetch the latest info on pages that have been modified since the initial caching, saving Internet bandwidth. Moreover, with PWAs, it is possible to access the same cached pages from different devices. You would cache the pages on a desktop, then the cached pages are synched to the PWA on a second device such as your phone at home over wifi. Then you can revisit the same pages on the phone while riding the bus where Internet connection is spotty.
