Symbolism, Imagery, Allegory
There are many voices, opinions, narrative perspectives, and versions of the truth in the novel. (That's why it's so stinkin' hard to read.) The storytelling is fragmented, and the voices reflect the sense of multiple meanings.
Remember, the stories all come out through conversations between characters: Miss Rosa and Quentin, Quentin and Mr. Compson, Shreve and Quentin, and Sutpen and General Compson. Many of these voices overlap, and in a sense we must allow them to do so in order to make sense of the story. We often can't tell who is speaking, especially when the omniscient narrator enters or when Shreve and Quentin speculate on events.
This multiplicity of voices may reflect the ambiguity of Faulkner's feelings toward the South. It allows us to understand the Civil War through various perspectives and see that even within the South, everyone had their own opinion.