Box

As of today, computers are not physical computer stricly speaking. They are hosted on very big computers (even sometimes cloud) that starts multiple exploitation system using what we call hypervisors.
These hypervisors can be either low level (Xen, ESX) meaning started without the need of an OS or not (Virtualbox, Qemu, Hvf, HyperV).
Anyway, high or low level hypervisors beed to run a dedicated OS image, sometimes with OS 'additions' e.g. dedicated packages installed on clients that forbids platform independence.

The Platform is helping on that area, building OSes that are validated under our compatibility matrix.