Answer: These categories correspond to character development: if they're a changed person by the end of the story, they're a dynamic character; if they haven't changed at all, they're a static character.
Explanation: You can categorize the people that populate your stories as static and dynamic characters. These categories correspond to character development: if they're a changed person by the end of the story, they're a dynamic character; if they haven't changed at all, they're a static character.