Backing track to practice guitar:
This is a guitar-less version of the song, so I can test my knowledge on how well I know the structure and I can practice to the original speed.
Backing track to practice drums:
I can use this to practice drums at the speed that I need to with every other part. This is mostly so that I can play to speed, play with more confidence and know when any changes happen and where they are.
Drums ONLY:
This can be used to practice how well I know the structure of the song and play along once I have learnt that as general practice. I can also use this to learn how the drums change throughout the song.
As a general note, I can use all of these to study the song and listen for different parts that I might not have heard before, so that I can get this as close to the original as possible.