This page describes some virtual datacenter concepts.
For an introduction to virtual datacenters see myCloud view and https://abiquo.atlassian.net/wiki/pages/resumedraft.action?draftId=311370496
You can create an instance to copy disks of a VM to store as a VM template.
In private cloud with hypervisors, the platform saves the disks and a copy of the original template definition. But if the VM was captured from outside Abiquo, the platform saves the configuration of the VM. The platform stores the instance under the master template in the catalogue.
In public cloud providers, the platform saves the instance as a new VM template with disks and the configuration of the VM. Remember to enter a name that will help you to identify the instance template.
When you create hard disks for your VMs, the platform will destroy them when you delete them from your VM or undeploy your VM. In private cloud datacenters with hypervisors, the platform creates hard disks on the hypervisor datastore.
In contrast, volumes are persistent and independent of VMs. The platform creates volumes on external storage. Volumes are available in public cloud providers and they represent public cloud storage such as Azure Managed Disks.