VHD (Virtual Hard Disk) is a file format which represents a virtual hard disk drive (HDD). It may contain what is found on a physical HDD, such as disk partitions and a file system, which in turn can contain files and folders. It is typically used as the hard disk of a virtual machine.
VHDX is a Hyper-V virtual hard disk file format. VHDX has a much larger 64 TB storage capacity than the older VHD format 2TB limit. It also provides data corruption protection during power failures and optimizes structural alignments of dynamic and differencing disks to prevent performance degradation on new, large-sector physical disks.
You can choose to have a fixed size or dynamically expanding VHD or VHDX file.
Once you have the new .vhd or .vhdx file created and setup, you can copy or move it to any Windows 10 PC you want to mount it on.
When you mount a .vhd or .vhdx file in Windows, it will be added as a drive in This PC to open it from.
This tutorial will show you how to create and set up (initialized and formatted) a new VHD and VHDX virtual hard disk file in Windows 10.