Scout is a round, or dynamic character in that she changes throughout the course of the book. When we first meet her she's a very naive young lady who's still finding her way in the world. Due to her many and varied experiences, however, she gradually becomes more mature, developing a greater understanding of the world around her and the people who live in it.
Through her interactions with Boo Radley and her attendance at the trial of Tom Robinson, she comes to realize that life in Maycomb is very different than it appears on the surface, that this is a place where certain people—mockingbirds, as Miss Maudie calls them—are not accepted for one reason or another. In understanding this crucial point, Scout shows herself considerably more mature than most of the adults in town, who, unlike her, remain flat and two-dimensional, unwilling or unable to change.