在学习UWP的过程中确实有这个迷惑，在此分享一下。
- UWP (Universal Windows platform), Metro and WinRT are all result of Microsoft's latest changes, microsoft made so many changes to it's app frameworks in a very short period and i believe that's the reason behind that confusion, you and many other developers have.
- Here is the little Confusing story behind those frameworks:
- Metro Apps: For windows 8, Microsoft had plans to move everything to Tablet and phone, and start getting rid of PC, for that they invented that thing named Metro Apps. As you may have noticed, Metro apps, appeared once, and then after less than a year they disappeared.
- WinRT: As expected Microsoft Was wrong "PC still Alive" so they had to make an urgent release after the big fat failure of Windows 8, for that they released the Windows 8.1, and they pushed all the ideas they had into that release (majority of the ideas were at beta and not complete as WinRT), WinRT was the main framework distributed under windows 8.1 for the first time, WinRT was tended to replace Metro Apps and mainly to replace the Old Windows API "Win32".
- UWP: Universal Windows Platform Apps, was finally released under Windows 10, and you can consider it as an successor of the WinRT, it's the same technology, but just different Version with a bit of features, main feature UWP has is that all UWP Apps can run in PC, Tablet And Phone with almost the same binaries. it's still fresh technology but it's worth learning for near future.
- As for WPF: is the Old framework that was invented to make Rich UI Applications For PC.
- Windows Forms: A very Dead Technology, it's only under maintenance now, no updates will be released anymore for that.
- You might notice that all those Technologies WinRT, UWP and WPF have similar syntax, Objects, Controls...etc, but don't let that fool you WinRT, UWP are not Based on WPF at all, though they both have .xaml files.
转载自：http://stopbyte.com/1678/what-is-the-difference-between-winrt-uwp-universal-windows-platform-and-wpf
Wei