Universal Windows Platform (UWP) apps embody a set of design principles that emphasize simple user interfaces that are centered around content that automatically adjusts for different screen sizes on different devices. You create the UI in XAML markup, and the code-behind in native C++. You can also create components (DLLs) that can be consumed by UWP apps that are written in other languages. The API surface for UWP apps is the Windows Runtime, which is a well-factored library that provides a wide variety of operating system services.
Tip
For Windows 10, you can use the Desktop App Converter to package your existing desktop application for deployment through the Windows Store. For more information, see Using Visual C++ Runtime in Centennial project and Bring your desktop app to the Universal Windows Platform (UWP) with the Desktop Bridge.
The Windows Runtime C++ Template Library provides the low-level COM interfaces by which ISO C++ code can access the Windows Runtime in an exception-free environment. In most cases, we recommend that you use C++/CX instead of the Windows Runtime C++ Template Library for Universal Windows Platform app development. For information about the Windows Runtime C++ Template Library, see Windows Runtime C++ Template Library (WRL).