What do we call the main idea or underlying meaning of a literary work?

The main idea or underlying meaning of a literary work is referred to as the theme. The theme encompasses the central concepts, beliefs, or messages that the author wants to convey through the narrative. It often addresses universal human experiences and can be expressed through various literary elements such as character actions, settings, and symbols.

In contrast, plot refers to the sequence of events that occur in the story, detailing how the narrative unfolds. Characterization involves the methods by which an author presents and develops characters within the story. Setting pertains to the time and place in which the narrative takes place, creating the backdrop for the action. While all these elements contribute to the richness of a literary work, the theme specifically encapsulates the deeper significance behind it, making it a crucial aspect in understanding literature.