What do Deployments and StatefulSets have in common?

Both Deployments and StatefulSets are controllers that manage a group of Pods, and the definition for these Pods (including the container images, ports, environment variables, etc.) comes from a common `PodTemplateSpec` within their respective configurations.

While StatefulSets support the `OnDelete` update strategy, Deployments primarily use `RollingUpdate` as their default and generally preferred strategy for graceful updates.

StatefulSets provide ordered, graceful deployment and scaling, especially important for stateful applications, but Deployments typically aim for speed and availability without strict ordering guarantees for individual Pods.

StatefulSets maintain a sticky, persistent identity for each of their Pods (stable network identities, persistent storage), whereas Pods managed by Deployments are largely interchangeable and stateless.