About an Universal Windows Platform project
An Universal Windows Platform application is a software that is installable on every device that runs Windows 10 because it uses an API that is in common with all the different API of different devices. It is published on Microsoft Store and it is available for HoloLens, Surface Hub, Xbox, Pc with Windows 10, Mobile and Devices + IoT.
The main idea is to write one code for different devices. We can do it because we use tools for common input Handling and techniques that help UI design.
Very simply an Universal Windows Platform application is made up of different pages. All of these are made up of two parts. The first part is a .xaml file. It takes care of front-end and everithing about interface and user experience. The second part is a .xaml.cs file that is called code behind that is the back-end. It takes care of the different events when an user interact with the application. It is easy to imagine that they are two linked files.
Every UWP project contains a .appxmanifest.
“The package manifest is an XML document that contains the info the system needs to deploy, display, or update a Windows app. This info includes package identity, package dependencies, required capabilities, visual elements, and extensibility points. Every app package must include one package manifest.”
[…] from docs.microsoft.com.
Obviously a UWP project isn’t a stand-alone application. It is from a solution that can contains different project. In this way the UWP project can interact with other projects.