A round character, also known as a dynamic character, is a type of character in a story who experiences growth, change, and development throughout the story. Unlike flat characters, who remain the same throughout the story and serve as background characters, round characters have complex personalities, motivations, and experiences that shape who they are and how they respond to the events of the story. They are often the main characters in the story, such as the protagonist, and their growth and change is a key part of the story's conflict and resolution. A foil, on the other hand, is a character who contrasts with another character in order to highlight their unique qualities and traits.