Creating a "virtual machine" with VirtualBox or VMware is misleading, no "virtual machine" is created, only a virtual view of the real underlying hardware, which must be physically present. Usually, "virtual" refers to something that doesn't exist at all, which is not the case here.
In comparison, platforms emulators are real virtual machines. For example, MAME can emulate hardware that doesn't physically exist anymore. In that sense, it can really create a "Virtual Machine".