Volume
A directory accessible to containers in a Pod, used to share data or persist state beyond a container's lifetime
A Volume is a directory that containers in a Pod can read and write. It solves two problems that container filesystems alone cannot: sharing data between containers in the same Pod, and preserving data when a container restarts.
Kubernetes supports many volume types. emptyDir creates a temporary directory that lives as long as the Pod. hostPath mounts a directory from the node’s filesystem into the container. configMap and secret volumes mount the contents of those objects as files. persistentVolumeClaim connects the Pod to a PersistentVolume for durable storage.
Volumes are defined in the Pod spec and then mounted into each container individually at a specified path. Multiple containers in the same Pod can mount the same volume, which is the foundation for sidecar patterns where a helper container processes data written by the main container.