Both flashback and foreshadowing are part of a much larger arsenal of literary techniques authors resort to when trying to pull readers into the reality of a story and reveal its characters. Whether you are writing your first short story yourself or reading the work of a master, it helps to know the difference between these two drama-heightening techniques.
Flashback and foreshadowing are different ways to accomplish the same end: to introduce events that are not happening in the story’s current moment. While flashback, as suggested by the name, takes the reader back into a past moment, foreshadowing hints at or presages an event that has yet to come. Done well, both can increase a story’s dramatic tension and deepen a character’s development. Both also play on the difference between story time, or that experienced by the characters living the story as it unfolds, and discourse time, or that experienced by whoever is reading the story.
A famous example of foreshadowing comes from Shakespeare's "Romeo and Juliet," where Romeo tells his love "Life were better ended by their hate/ Than death prorogued, wanting of thy love.” By this he means that he'd rather live a shorter time and have had her love than live a full life without it. As he finds both her love and an untimely end, the line foreshadows his fate. Homer employs flashback in "The Odyssey," when Odysseus relates his earlier experiences to other people. This allows Homer to fill the reader in on Odysseus' past without spending undue time in boring narration.
Flashback is an important technique for character development. When readers begin stories, they meet characters with pasts and personalities that require fleshing out. Extended narration or dialogue to achieve these ends can be boring and stilted, so instead flashback is often employed. The author uses previous events not only to explain current events in the story but also to deepen the reader’s understanding of how a character might respond to a given situation.
Foreshadowing is a less concrete technique than flashback. While the latter simply relies on a detour in time to a previous moment, foreshadowing is often used to build suspense toward a major event or finale that the reader has yet to experience. Because giving the surprise away destroys narrative tension, authors must use foreshadowing carefully to drop hints about what is to come. The best types of foreshadowing keep the hinted-at event a surprise, but are obvious to the reader in retrospect as pointing to a single outcome.
Most stories do not rely on a single linear narrative flow. Instead, they employ time-switching devices such as flashback and foreshadowing to draw readers in and help them understand the current moment in its full context. While flashback builds drama by steadily deepening a reader’s understanding of characters and story, foreshadowing does so by hinting at greater events to come. Good pacing relies on sprinkling each technique throughout the story rather than simply piling them all in one place, thereby letting the reader in a little at a time.