Storageclass

Containers are designed to be stateless and ephemeral. To run stateful applications like PostgreSQL, MySQL, Redis, or Elasticsearch, Kubernetes provides storage abstractions that decouple persistent storage infrastructure from application workload definitions.

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.