There are five according to Aristotle
Hamartia – a tragic flaw that causes the downfall of a hero.
Hubris – excessive pride and disrespect for the natural order of things.
Peripeteia – The reversal of fate that the hero experiences.
Anagnorisis – a moment in time when hero makes an important discovery in the story.
Nemesis – a punishment that the protagonist cannot avoid, usually occurring as a result of his hubris.
Catharsis – feelings of pity and fear felt by the audience, for the inevitable downfall of the protagonist.