What is better a cd or a tape?

Remastering is, at its core, the process of creating a new master for an album, movie, or any other creation. It tends to nowadays specifically refer to the process of porting a creation from one medium to another, but this is not always the case. For example, a vinyl LP originally pressed from a worn-out copy tape many tape generations removed from the "original" master recording could be remastered and re-pressed from a better condition tape.