What happens if a file is deleted on eg. phone?

What happens if i delete eg a photo from my phone?, will it be deleted on the mycloude2ultra also og will it stay there?

It will get deleted from the NAS.

It’s a backup not a sync, the picture will stay on the NAS.

Assuming you are referring to the MyCloud mobile app that automatically uploads your pictures to the NAS.

If you are using a filemanager on your phone that has access to the NAS and you delete a file there it wil indeed be deleted from the NAS.

My bad.

I know the way the system USED to work; if you deleted from the NAS - - > it would get restored from the phone.