Edge and IE - progressive web apps and universal web apps

PWAs are just web sites 'that took the right vitamins and progressively become apps'. This means they take advantage of modern platform features when they are available.

A PWA is many things, which is more than I can fit in this reply, https://love2dev.com/blog/what-is-a-progressive-web-app/

You are right IE is pointless at this time. It only survives for enterprises to lazy to upgrade internal applications from 2008 web standards....

PWAs in Windows are slightly different than PWAs in Chrome on Android because the overall platform and usage scenarios differ.

I would not worry about how they are executed, but they are executed using the EdgeHTML and Chakra engines.

PWAs in Windows are equivalent to UWP apps. They have full access to platform features, etc. Of course most apps wont need that level of access, so the store may not be the right option for all web apps.

I don't know if the LinkedIn app is a UWP or it is a PWA. I don't know that they would have too many platform integrations other than a possible Live Tile. But I don't work for that team so who knows.

MSFT is quickly making any of the web properties PWAs, so it might be.

Feel free to ping me with any PWA questions you may have.