Terminology
* Availability Zone - it is represented by all resources (Nutanix Clusters) connected to Prism Central or Xi Leap Availability zone. Depends on the architecture, Availability zone can represent geographic territory, datacenter or server room in the datacenter. Protection policies - in protection policies you set up (RPO, Retention), rules to auto-apply policies to virtual machines
https://vmwaremine.com/2019/02/08/nutanix-leap-runbooks-part-1/#sthash.VwrzSzhQ.dpbs

https://portal.nutanix.com/page/documents/details/?targetId=Web_Console_Guide-Prism_v4_7:lic_licensing_managing_c.html Reclaiming Licenses (Including License Renewal) You can reclaim and optionally re-apply licenses for nodes in your clusters:
* You must reclaim licenses when you plan to destroy a cluster. First reclaim the licenses, then destroy the cluster. You do not need to reclaim Starter licenses. These licenses are automatically applied whenever you create a cluster, including after you have destroyed a cluster.
* Return licenses to your inventory when you remove one or more nodes from a cluster. Also, if you move nodes from one cluster to another, first reclaim the licenses, move the nodes, then re-apply the licenses.
* You can reclaim licenses for nodes in your clusters in cases where you want to make modifications or downgrade licenses. For example, applying an Ultimate license to all nodes in a cluster where some nodes are currently licensed as Pro and some nodes are licensed as Ultimate. You might also want to transition nodes from Ultimate to Pro licensing.
* You must reclaim licenses when you renew licenses. First reclaim the expired licenses, then apply new licenses.