I noticed while editing the "Basic Form Metadata" that any changes are implicitly saved to database. So, am wondering what is the use of "Save" and "Save & Close" buttons? Is this the case on all screens of the Portal Management App or is it only with "Basic Form Metadata
Its not specific to Power Pages, its saving because your Dataverse Environment has autosave turned on (a setting under Advanced Settings->Settings->Administration->System Settings that is now turned on by default). Also, the save is an inactivity save and navigate away from save (and not all actions result in a save).