I'm stuck at getting the clear and sharp difference between these two words. WikiDiff says:
As nouns the difference between apparition and ghost is that apparition is an act of becoming visible; appearance; visibility while ghost is (rare) the spirit; the soul of man.
Longman defines apparition as:
something that you imagine you can see, especially the spirit of a dead person.
and ghost as:
the spirit of a dead person that some people think they can feel or see in a place
So, what is the exact difference between these two?