Kubernetes Request is used to ensure a Pod has enough defined resources available. It is possible for the Pod to use more than what is specified. This is considered a soft limit.
Kubernetes Limit is a used to ensure a Pod does not use above what is specified. This is considered a hard limit.
Kubernetes Resource Quotas is used to limit resource usage per namespace.
Kubernetes Pod Priority and Preemption is a used to apply priorities to pods relative to other pods. If a pod cannot be placed on a node, it may preempt or evict lower priority pods.