When you add an ESXi 6.x host to a new Cluster, which vSphere object owns the CPU and Memory resources of the hosts?

vCenter Server is the management platform that provides visibility and control over resources, but it does not own or allocate the underlying CPU and memory of ESXi hosts.

A Datacenter is a top-level logical container in vCenter used for organization, not a resource management object that owns host compute resources.

In vSphere, a Cluster is a resource pool that aggregates the CPU and memory of all member ESXi hosts into a single logical pool. Features like DRS and HA operate at the cluster level by managing these pooled resources, making the Cluster the authoritative owner of host resources once a host joins it.

Once an ESXi host joins a cluster, its resources are ceded to the cluster's resource pool - the host itself no longer independently owns or schedules those resources.