Persistent storage in the container world is a serious issue. When we studied Docker images, we learned that the only storage that is persistent across container runs are the layers of the image, and they are read-only. The layer where the container runs is read/write, but all data in this layer is deleted when the container stops. With pods, this is the same. When a container dies, the data written to it is gone.
Kubernetes has a set of objects to handle storage across pods. The first one that we will discuss is volumes.