In the case of a free product like VirtualBox where you're not paying for tech support, there isn't a difference.
Unless you mean that there is a difference between what merely happens to work and what the developers strive to ensure works. In this case, VirtualBox definitely "supports" using physical disks and partitions (though they describe it as an "advanced" feature).
Unless you mean that there is a difference between what merely happens to work and what the developers strive to ensure works. In this case, VirtualBox definitely "supports" using physical disks and partitions (though they describe it as an "advanced" feature).