One way in which they were different was in the book it described Grandma Sands as being a small, pruny, old lady whereas in the movie she was a young, large-framed lady. A second way the two stories were different was in the book, Joetta had no clue about the bombing, while in the movie Joetta knew that a bomb went off in her church. Finally, the two stories were different because in the book, Byron kissed the mirror on the car, but in the movie he kissed a window.
There are several details about the story that we did not know from the movie because the movie had a different focus than the book. The book focused more on how the kids are growing up and how their personalities are affected because of the events that occurred, whereas the movie focused more on the Civil Rights Movement. If the movie added all the details from the book, it would be really long and it might not flow as well, which might make it boring.
I believe the movie was told very differently than the book because a movie director is entertaining a different audience than an author of a book. A director has different goals and thoughts to portray than the original book. The director is given certain artistic freedoms to help better connect with the audience and sometimes that makes the story change a little