Predefined Approval Statuses
An item without workflow has an Approval Status of Undefined. An item in workflow but without a proper Approval Status has an Approval Status of Unapproved.
SDL Tridion Sites defines the following Approval Statuses out of the box:
Undefined- This non-modifiable status always has the lowest hierarchical importance. If an item is not in workflow and does not have a Workflow Association, its Approval Status is Undefined.
Unapproved- If an item is in workflow but does not (yet) have an Approval Status, its status is Unapproved.