I have a water leak, which looks like it has been caused by two parts rubbing together. Can someone identify these parts and should they be touching like they are?
No, they shouldn't be touching. Difficult to tell from your photo, but the silver pipe nearest the camera looks like coolant (hence the pink stain). The other one could well be air conditioning refrigerant.
It looks like the coolant is leaking from where the metal braided pipe meets the solid pipe and leaking on to the pipe nearby.
From the photo it doesn't appear that the other pipes are rubbing.