Storage
Persistent Volume
Storage that survives independently of the server or container using it, so data isn't lost when compute is destroyed.
A persistent volume is storage whose lifecycle is separate from the compute using it. Destroy the instance or the container, and the volume and its data remain, ready to attach elsewhere. This is the answer to the fact that many cloud resources are ephemeral by design, especially containers and autoscaled instances that come and go.
It matters most in two places. On a VPS, a detachable block volume lets you rebuild the server without losing the database sitting on it. In Kubernetes, a PersistentVolume is how a container that gets rescheduled to a new node keeps its state, since the container's own filesystem vanishes on restart.
The concept is a reminder to know which of your storage is durable and which evaporates. Local instance disk is often ephemeral. Attached volumes and object storage are not. Losing a database because it lived on scratch disk is a classic, avoidable mistake.