Priority classes define where pods are placed in the scheduling queue and whether the pods will make way for higher priority pods.
In the example below, pods whose priorityClassName is high-priority-nonpreempting will be placed in the queue higher than those pods with lower priority class value but will not preempt other lower priority pods due to preemptionPolicy: Never
apiVersion: scheduling.k8s.io/v1
kind: PriorityClass
metadata:
name: high-priority-nonpreempting
value: 1000000
preemptionPolicy: Never
globalDefault: false
description: "This priority class will not cause other pods to be preempted."Reference: https://kubernetes.io/docs/concepts/scheduling-eviction/pod-priority-preemption/