What Does Hyper-V Virtual Hard Disk (VHDX) Mean?
A Hyper V virtual hard disk (VHDX) is a disk image file format used to create a virtual hard disk (VHD) within Windows Server 2012-based virtualization environments.
VHDX enables creating and provisioning virtual/logical disk storage space to virtual machines. It is an enhancement to the previously used VHD file format in Windows Server 2008.