The Parallels Display Adapter (WDDM) is a Windows Display Driver Model (WDDM) driver used by Parallels Desktop, a software that allows users to run virtual machines (VMs) on their Windows PCs or Macs. This specific driver is used when you are running Windows as a guest operating system inside a virtual machine (VM) hosted by Parallels.

The Parallels Display Adapter (WDDM) is essential for enabling the guest operating system (typically Windows) to render graphics correctly within the virtual machine, allowing you to have proper display output, resolution settings, and support for multiple monitors. It's part of the virtualized graphics subsystem that Parallels provides for its virtual machines.