Let's move on to something more robust. There are two types of PersistentVolumes that we'll touch base with in order to explain how you can use AWS's and GCE's block storage engines to provide stateful storage for your Kubernetes cluster. Given that many companies have already made significant investment in cloud infrastructure, we'll get you up and running with two key examples. You can consider these types of volumes or persistent volumes as storage classes. These are different from the emptyDir that we created before, as the contents of a GCE persistent disk or AWS EBS volume will persist even if a pod is removed. Looking ahead, this provides operators with the clever feature of being able to pre-populate data in these drives and can also be switched between pods.