neowin[.]net/news/how-to-install-any-website-as-an-app-on-your-computer-with-edge-chrome-and-brave/
A Progressive Web App [PWA] at its very simplest is a web site, & a shortcut to that web site that opens it in a web browser. Of course there's little reason to go to any great lengths to say add a shortcut to your desktop for the GOTD site -- you can do it but it's hardly any better / faster than opening the browser & clicking the GOTD bookmark you've created. But how about a site like gmail[.]com... Since Gmail is totally web-based, there's no app from Google that you can install & use to send and receive emails using the service -- you have to open a browser window, go to the site, & log in. But, if you set the site up as a PWA, it'll work just like an installed app. The difference between that PWA and a regular software program is that instead of installing however many files to make the app work, everything's done on the Gmail web servers. In some ways it's the best of both worlds.
Microsoft made a push to get web sites tailored for use as a PWA in the Windows Store, IMHO as a way to fill it up, make it look like there was more there. Otherwise you set up PWAs by using the menus in browsers like Edge, Chrome, or Brave, and this Neowin article shows you how to do that.