The status of a case can fall into one of the following categories:
When you create a case, its status is automatically set to New if the Assigned To field is empty.
If the current case status is Assigned, Wait for Customer, or Wait for Third Party, you must first change it to Open before marking the case as Resolved.
Cases can be closed automatically through a default workflow in Vtiger CRM, and once a case is closed, it cannot be reopened. However, resolved cases can be reopened if necessary.
Resolved cases can be reopened if necessary.