What is the difference between themes, motifs, and symbols?

The theme of a novel is the idea or message the author is trying to convey. There can be major themes and minor themes. A major theme is the central idea of the novel. It is the overarching message expressed by the author. The minor themes are messages than generally accompany or support the major theme.

Motifs and symbols often get confused. Motifs specifically help explain the theme of the novel. They serve to further the reader's understanding of the theme. Motifs will consistently present themselves throughout the novel. Symbols, on the other hand, help the reader understand ideas outside of the the general theme. A symbol will only present itself once or twice.