The film and book share themes but are quite different.
In the film, people live in one city and believe the outside is poisonous. The plot is very different including how people die, why, what happens to runners, what sanctuary is and the ending. Despite the significant differences from the book, it's a good film and worth watching in it's own right.
Okay thanks. Yeah I watched like the first 10 seconds and when the title card explainef so many differences up front, I decided to take a break and let my mind kind of solidify the novel before I start on the movie, because I don’t want to conflate them later.