Host interactions
How the guest uses the hardware.
While all of the software here can use a physical disk partition for its storage, it’s more common to use a file as a virtual disk. Not only does this save having to manage lots of partitions, it also makes creating and moving virtual machines much easier.
Each of these programs will create such a file when setting up the virtual machine, but they each use their own format. However, some of them are able to work with different formats. VMware Workstation Player uses its own format and that’s pretty much it for the free version. Gnome Boxes, Aqemu and Virt-manager all use qemu behind the scenes and so are able to work with Qemu’s qcow2 format, VirtualBox’s vdi files and VMware’s vmdk files, although some features are only available when working with native qcow2 images.