According to the Nutanix Prism Central Admin Guide, a category is a grouping of entities into key-value pairs. Categories are used to group entities (such as VMs, hosts, or subnets) based on specific criteria (e.g., Department: Marketing or Environment: Production).
Once entities are assigned to a category, administrators can link policies (such as security, protection, or automation playbooks) to the category rather than to individual entities. This allows for scalable and dynamic management, as any new entity tagged with that category will automatically inherit the associated policies.