In order to conclude a successful feature delivery the deployment confirmation in the production system is the last step. In this step you are confirming that the changes done via the feature are properly delivered to your production system. As soon as all features related to a requirement are confirmed the requirement is done.
To prepare for the deployment confirmation you should do the following checks:
By confirming the deployment of a feature you are conducting the feature and no further changes to it are possible. The final state "Deployed" indicates that the feature was delivered to production properly.