Allegories refer to any piece of writing which have a hidden message.
The hidden message most often refers to one of a political or moral
nature. Hotel Rwanda, a movie about a man who shelters hundreds of
people from mass genocide in Rwanda explores the themes of genocide and
taking charge for one's own safety. It is an example of allegory.
A
commentary on the other hand refers to a piece of writing or visual
which offers opinions about a specific topic or tries to explain a
certain phenomenon in greater detail.
The similarities between the two are: they both deal with factual instances, they are both serious in nature.Hope this helps
