Motive: Why your character wants it.
Conflict: What or who is stopping your character from getting it.
External: The goal, motive, and conflict that is more apparent to other characters in your story.
Internal: The goal, motive, and conflict that has to do with the more emotional part of your character.
As a writer you need to be aware of both internal and external goal, motive, and conflicts of your main characters. Even with minor characters, goal, motive, and conflict are important to the story. Being aware of these beyond the surface - the bad guy is just killing people to be bad - gives more depth to your story. It can weave characters and plot lines together. It makes the reader relate with your characters. If you are getting stuck knowing just what your characters are supposed to do next - it might be because you are not completely in tune with your goal, motive, and conflict.