Each environment overlay should place rendered objects into a different Kubernetes namespace without editing every resource’s metadata.namespace by hand. Which kustomization field does that?
Select an answer to reveal the explanation.
Short Explanation
The namespace field is the destination stamp on every envelope leaving the overlay printer. One line, and namespaced resources head for staging or prod without rewriting each file.
Full Explanation
Setting namespace in kustomization.yaml applies that namespace to eligible resources in the build, which is the standard per-environment scoping approach. Image tags, decorative labels, and secretGenerator entries do not relocate Deployments into another namespace by themselves.