Supporting characters are individuals in a story who help to develop the main character and advance the plot. They often provide assistance, guidance, or even obstacles that the protagonist must overcome. These characters can include friends, family members, mentors, or rivals, and they add depth to the narrative by showcasing different perspectives and relationships. In many stories, supporting characters like sidekicks or antagonists play crucial roles in highlighting the main character's traits and growth. For example, a best friend might encourage the hero to take risks, while a villain challenges them to confront their fears. Together, these characters enrich the storytelling experience.