Final answer:
The Song of the Cid differs from other classic epics primarily in its minimal supernatural interference and more realistic portrayal of its protagonist's activities, focusing less on philosophical themes.
Step-by-step explanation:
The Song of the Cid, while sharing many common features with classic epics, diverges most notably in its lack of extensive supernatural interference. The other significant difference lies in how the epic presents its story and characters in contrast to epics like Homer's The Iliad and The Odyssey, or the Epic of Gilgamesh. These epics contain many layers of narrative and multiple subplots, which can give rise to several different stories or tragedies from each larger work. In contrast, The Song of the Cid focuses more on the realistic portrayal of its hero's military and political deeds. Moreover, while the epics mentioned often present philosophical and existential themes, such as debates on morality, the pursuit of immortality, and human virtues like arete, The Song of the Cid primarily showcases a historical figure and his role in society without delving deeply into such philosophical explorations.