Why does Agatha Christie separates her book into three sections?

Agatha Christie separates her book into three sections: "The Facts," "The Evidence," and "Hercule Poirot Sits Back and Thinks." How would you explain the difference between facts and evidence? ... Therefore, all facts are not evidence, because evidence may just be a red herring or misinterpreted and not true.

Explanation:

thick as the foliage of the waving wood; the figurative language that is used here is referring to a battle. there are two mountains that are facing opposite of each other, and they have armies better stick like a forest.

the book's theme is the moral ambiguity of the iranian revolution, history of middle eastern relations and the process of growing up during war. it sheds light on the stereotypical views of middle eastern culture and religion.

the author explicitly portrays the issues of class disparities and racism continously throught the whole novel.

the relationship between parents and childrens, the abandonment of faith, modernity vs fundamentalism and class conflict are the 4 main panels that this novel englobes.

hope this , if you would like me to be more specific about a specific excerpt let me know : )