Parent Form Binder is intended to be used in a Subform where the subform data will be saved using the parent form's store binder instead of itself.
In Joget Workflow v5, the Parent Form Binder extends the scope of what the Joget Workflow v4's Parent Form Binder supports.
Unlike the predecessor, the new Parent Form Binder now passes the data contain within itself to the immediate parent's binder instead of just using the parent's binder's table name to perform storing.