A Deployment update changes the Pod template and records a new revision. The controller rolls replacement Pods according to its strategy, retaining enough history for supported rollbacks. Rollout status reports progress; it doesn't choose the next image for you. Restart repeats the current template, while undo restores a previous recorded template. Those operations have different outcomes when the new image can't start. Keep the Deployment identity and desired count through the change. These tasks move an application to a selected release and recover from one deliberately broken release. Inspect the resulting template instead of treating the last command's success message as proof. A blue-green switch selects a prepared release through a stable Service. A canary adds bounded new capacity alongside stable replicas; replica counts alone don't guarantee a request percentage.