B A C K S T O R Y
I've run into the term backstory enough times recently to merit a post on this technique used in writing fiction, and perhaps some creative nonfiction, as well.
Backstory is anything that happened before the present story begins. It's helpful to give your readers some background on the characters with this method, helps to paint the character for the reader. It also shows the reader why whatever is happening now is important to the character. Another way to do that is to write a prologue for a novel which shows and/or tells about something that happened earlier that has a momentous bearing on the story to come. The prologue is meant to hook the reader immediately.
Backstory works, too, and is used in short stories but also novels but it's sprinkled throughout the entire story, not standing alone as in a prologue. What if a young woman falls overboard during a storm on a large lake? It might help the reader to know that she had been the star on her high school swim team. How about if a story opens with the protagonist shooting an escaped convict? If we're told that the man shooting the gun had an experience years earlier that made him terrified of guns, it puts a different light on what is happening.
One thing to remember is that the reader does not need to know as much backstory as the writer does. The writer develops the characters and knows intimate details that make the characters the people they are and how they react to particular situations. Give the reader enough information but don't overwhelm them.
For me, the concern about backstory is that the writer will give so much backstory that it begins to overshadow the main event. Given in small amounts, it works but go on for paragraphs of backstory and the reader can lose the train of thought in the action of the primary story. Like so many things in life, the backstory needs to be used in moderate amounts. That old adage Moderation in all things applies to using this technique.
There are those who teach writing classes that will suggest eliminating all backstory. They might claim that it weakens the main story. And it might do so if you don't find that healthy balance. My own feeling is that you might sprinkle it through the story like Tinkerbelle does with her Fairy Dust. But don't dump a whole lot on at one time.
If you would like to read a little more about the use of backstory, Jan Fields, editor of Children's Writer eNews, has a discussion going on the topic. The techniques in writing children's fiction are the same as for adult fiction, so what is being discussed works for all fiction writers. Take a few minutes and look at the discussion questions and answers here.