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.
For one project we developed and tested software on Windows OS. It is used with coolers, motherboards, keyboards, mice and other hardware and peripheral devices. We use VHD files for testing hardware on Windows.