You might have heard the writing advice: No back story for 50 pages. Here’s a nifty article about why, and how to use “character history” instead. Yes, I am being a tad sarcastic. There isn’t really a difference between the two, except in this author’s view, character history is quick flashes of related information needed to understand the character motivations at the time they’re needed. Back story is the blocks of unessential information not absolutely pertinent to the situation. Good stuff.