A pod is not self-healing. When a pod encounters failure, it won't recover on its own. ReplicaSet (RS) and ReplicationController (RC) therefore come into play. Both ReplicaSet and ReplicationController will ensure a specified number of replica pods are always up and running in the cluster. If a pod crashes for any reason, ReplicaSet and ReplicationController will request to spin up a new Pod.
After the latest Kubernetes, ReplicationController is replaced by ReplicaSet gradually. They share the same concept, just using different requirements for the pod selector. ReplicationController uses equality-based selector requirements while ReplicaSet uses set-based selector requirements. ReplicaSet usually ...
