The fundamental message of a novel, story, or poem is the "theme," and may be stated directly, or implied, meaning readers must determine the theme by context. The overall meaning of the text is that which readers can apply to life.
While there are times an author states his main idea or stated theme to his audience, authors more often use implied themes, getting their message across through circumstances and the emotions of their characters. Many themes, such as love, friendship, trust, peace, struggle and betrayal, are universally understood. Some stories have several themes, which may be expressed in both stated and implied terms.