Vladimir Propp was a Russian scholar who analyzed Russian folk tales and identified common narrative structures. He identified 31 narrative units that comprised the typical structure of many Russian folk tales. These units included character archetypes like the hero, villain, dispatcher, donor, and helper. Propp broke down how these characters interacted and progressed the story. For example, the villain acts against the hero while the dispatcher sends the hero on a quest and the donor provides assistance. Propp's theory provides a framework for understanding recurring patterns in folk tales and has been applied to other stories like the Harry Potter series.