Volumes

By default, all files created inside a container are stored on a writable container layer. When that container is deleted, the data is destroyed. Docker Volumes solve this by storing data outside the container filesystem.

Containers are ephemeral by default—when a container restarts, all data written to its local filesystem is lost. On the CKAD exam, you must demonstrate how to attach persistent storage to Pods using PVCs and StorageClasses.