VMware uses a format called virtual machine disk (VMDK) while Microsoft uses a format called virtual hard disk (VHD) to store your virtual disks. Both these companies offer excellent virtualization software, but unfortunately they’re not compatible with each other. For example, let’s take the two largest players in this industry - Microsoft and VMware. Also, this demand has fueled different vendors to offer virtualization software, each in a different format. The many benefits of virtualization software have led to an increase in its use among businesses the world over.