What exactly is “character motivation”?

I was at a writers conference when I first heard the term “character motivation.” The visiting author had kindly agreed to look over a few pages of my first Lawmen of Clayton County novel and informed me I should think more about the motivation behind Niccola and Charles. Unclear on the term, I just blinked and we went on, but I thought about it a lot later.

What exactly did that mean?

After months of editing and growing as a writer, it slowly sunk in: I hadn’t clearly defined why the characters were motivated toward their goals. In a novel, there has to be a reason for every action. Why did Niccola and Charles move out west? Why did she stay with him, and why was he so determined to marry her? I didn’t really know at that point, so I pondered these questions for a while.

Later, with the help of my fabulous writing coach, I learned the importance of thinking through all the reasons for my characters’ thoughts, words, and behaviors. I also began to recognize these subtle explanations in the work of authors I admired. After months of practice, inserting little explanations for  my characters’ goals into my stories is becoming easier.

What motivates your characters to behave the way they do?