What does the "nodeSelector" within a PodSpec use to place Pods on the target nodes?

Annotations are used for non-identifying metadata and do not influence Pod scheduling decisions like `nodeSelector` does.

While nodes have IP addresses, `nodeSelector` does not directly use IP addresses for scheduling; it relies on labels for declarative node selection.

Hostnames are identifiers for nodes, but `nodeSelector` operates on arbitrary key-value labels, offering more flexible and generic selection than just hostnames.

The `nodeSelector` field in a PodSpec takes a map of key-value pairs, which are then matched against the labels assigned to nodes. Only nodes that possess all the specified labels will be considered for scheduling the Pod.