What does OVF/OVA format allows to be done to a VMware template or Virtual Machine?
Automate VM deployment
The true definition for an OVF/OVA file is that it is an "Open" format that is able to be "Transported". This means the VM can be literally transported between different cloud systems such as Amazon, Google, and MS.
Any cloud provider that supports this format can have the VM imported into their cloud system.