Zend certified PHP/Magento developer

ISO vs Virtual Disk (qcow2, vhd etc.)

What are the actual technical differences apart from ISO being read only and their purposes? Can I convert an ISO image to a virtual disk (Ex: qcow2) without changing its content? If that is possible how can I do that? Can I use a virtual disk image (Ex: qcow2) as an installation media in place of an ISO image for a VM?

The use case: Most cloud providers only support virtual disk images such as qcow2 and they don’t support installing the OS from an ISO. Instead they use preinstalled OS images (virtual disks). What I want is to run the installation program just like from an ISO but using a virtual disk instead (Ex: qcow2)? I think it should be possible just as we can make bootable flash drives out of ISOs in the physical world. Installation program needs to be run. That’s the requirement.