A Thousand Splendid Suns is told by an omniscient narrator who knows the past and the future and the characters' thoughts. He does not have a definite personality - he is not a specific person, who is telling this story for reasons that matter in a world outside of the story itself. He is merely a storyteller, telling the story for its own sake, creating characters and describing them to the reader for the reader's entertainment and education.
A Thousand Splendid Suns