Prism Element and Prism Central Management
Two consoles, two scopes
Prism Element is the management plane of a single cluster: hardware, storage, VMs, alerts, tasks, health, and that cluster's REST API. Prism Central is a separate VM, or a cloud-hosted instance, that registers many clusters and adds cross-cluster features - categories, projects, self-service, reporting, and products such as Calm, Flow, and NCM.
What lives where
Categories are key-value labels applied to VMs, images, and other entities; they drive policy, search, and self-service. Projects group users, quotas, and resources for delegated provisioning. Tasks started in Prism Central appear in the PC task list, while work performed directly on the cluster appears in Prism Element. Alerts also differ: PE raises cluster-level alerts, and PC aggregates them across registered clusters.
Traps
A common trick is implying Prism Central is required to run a cluster - it is not; a cluster is fully manageable from Prism Element. Another is confusing a category with a project, or assuming a Prism Central version automatically matches AOS: PC has its own release train and a compatibility matrix with AOS versions.
Rule of thumb
Single cluster with deep hardware and storage work, use Prism Element. Many clusters with policy, categories, and delegated users, use Prism Central.