Aristotle suggests there are three differences between art forms according to his work Poetics.
1) Means - the medium used such as language in literature or instruments in music.
2) Objects - the characters depicted which can be better or worse than real people.
3) Manner of imitation - how the story is communicated such as simple narration, narration through a character, or dramatic representation of events. Aristotle emphasizes tragedy should provoke pity and fear in the audience.