WTF are Progressive Web Apps?

Publishers can get all the benefits of the mobile web with all the functionality of mobile apps thanks to Progressive Web Apps... Here’s a primer:
- build a mobile website that can perform super-fast and behave just like an app... lets people interact with it like an app without the hassle of downloading it.
- can load on a number of browsers and devices, regardless of screen size and other specs... work across the board without as big an investment as native apps designed for every particular platform.
- They learn more about the user
- could invite a reader to get notifications just like an app. It’s also dynamic and can update with new content on its own, and be accessed while offline.
- will only become more sophisticated with more integration into the devices
- Accelerated Mobile Pages are designed to load fast on mobile devices, and PWAs are just as fast but with more functionality. However, AMPs are actually indexed in Google search ... PWAs require a direct URL or link.
- There are other downsides to PWAs, as well, including the inability to serve ads.