GMC

Question: What is GMC? Answer: Goal, Motivation, Conflict

What does he/she want? (goal)
Why does he/she want it? (motivation)
Why can't he/she get it? (conflict)

Answering these questions helps us clarify our story so we don't muddy it up with unnecessary information. It also helps us know our characters better and hopefully makes our writing tighter. Each main character should have a STRONG GMC.

Let's say our Hero is Tyler.
What does he want? Revenge for his parents murder by villain
Why does he want it? Because as a result, he grew up without love, homeless and penniless
Why can't he get it? The villain is a high-ranking government official. He's also the brother of the woman Tyler loves.

The character's goal gives a reason for the story to open. In the beginning, the reader should identify and understand this goal. If the reader personally agrees with this goal, all the better.

The character's motivation keeps him trying, getting in and out of scrapes and situations as he tries to reach his goal. By this time, the reader should care deeply about the character, care if he fails or succeeds. The reader wants him to attain his goal, not just because it's a worthy goal, but because they care about the character personally.

The conflict, or what keeps the character from succeeding, should be big enough that the reader can't imagine how the character could possibly succeed and they HAVE to read on to discover how it could possibly work out. (I'm talking about stories that have a HEA (happily ever after) ending, since those are the kind I like.)

Actually, since each minor character is the hero of their own story, try to give a nod to each character's own GMC. If there is a villain in your story, that person's GMC is just as important as the hero/heroine's GMC, especially because the villain's goal is usually in direct conflict with the hero's goal.

Full books have been written about this topic. I've merely scratched the surface here. But one of the best examples of strong, clear GMC is The Count of Monte Cristo by Alexandre Dumas, both the book and the movie. (The movie is, IMO (in my opinion), very well done.) If you are interested in seeing GMC in action, I would recommend watching it.