Windows 10X is a new flavor of Windows 10 designed for dual-screen devices such as Microsoft’s own Surface Neo. Microsoft has released an emulator that can be installed on Windows 10 Insider builds and you can learn more about it here. The OS is technically separated from the OS components such as the drivers and apps. Microsoft says it can install updates in less than 90 seconds and it requires only one reboot. Microsoft also said Win32 apps won’t be able to use the system tray and classic File Explorer cannot be modified.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10x-to-feature-faster-updates-win32-apps-support/