I am interested in the topic, but unfortunately I know too little about it. What exactly does “35mm scan” mean? I assume that it means that an original camera negative is scanned and not just any copy of a copy of this negative? What are the advantages of a 35mm scan?

I have become very cautious after many bad purchases. About 16 years ago I read a review of the Cinderella DVD in a DVD magazine (which called itself a “professional magazine”). It praised the outstanding, restored picture, which was now free of dirt and offered beautiful colours due to the remastering.
I then bought this DVD without knowing what terrible things had been done to the picture …