The theme is a story’s moral judgment of character ,general subject matter, observation about life , point of view on a difficult topic

Definition of Theme As a literary device, theme refers to the central, deeper meaning of a written work. Writers typically will convey the theme of their work and allow the reader to perceive and interpret it, rather than overtly or directly state the theme. Since Theme and main idea are important components of any story. The main difference between the theme and the main idea is, the theme is a lesson or a moral whereas the main idea tells us what the story is about.

this is a good question! i'll do some research and come back when i have the answer!