The Categories of Apps in Windows 10

In simple terms, Windows applications can be divided into 3 categories, Win32 apps, Windows apps, and UWP apps.

Win32 apps

Traditional Windows applications, sometimes we call them desktop apps. For example, WiseCleaner series applications.

Windows apps

It was introduced in Windows 8, primarily installed from the Store app.

UWP apps

The full name is Universal Windows Platform applications, designed to work across platforms, and can be installed on multiple platforms including Windows client, Windows Phone, and Xbox. All UWP apps are also Windows apps, but not all Windows apps are UWP apps.

Subdividing Windows apps can be divided into 2 categories:

System apps

Apps that are installed in the C:\Windows* directory. These apps are integral to the OS. E.g., File Explorer, Microsoft Edge Legacy, Cortana, and so on.

Non-System Apps

All other apps, installed in C:\Program Files\WindowsApps. There are two classes of non-system apps.

• Provisioned: Installed in user account the first time you sign in with a new user account. E.g., 3D Builder, OneNote, Paint 3D, and so on.
• Installed: Installed as part of the OS. E.g., BingNews, Sway, Remote Desktop, and so on.

[Reference]

Microsoft Docs: Apps in Windows 10