Building the Arc
Life is change; life is problems and challenges; life is reaction and response. All these things also are what make a character and a story come alive, and the process of their change and evolution is the arc.
A character arc begins with the character's state of being at the beginning of the story, and follows the course of his/her evolution to whom he/she becomes by the end of the story.
The story arc is similar, but for the tale itself: It follows a logical sequence of events that lead from the state of affairs in the beginning, to the resolution of matters in the conclusion.
What happens between that starting point and the conclusion is the story.
Before you submit a fiction manuscript, look at your characters. Have you established an arc for each of them? Even the small ones, the bit-part players, should be granted some arc, some ability to evolve, while the main characters' arcs will naturally be more in-depth. A character who stubbornly maintains his/her beliefs from page one to 'The End' is a boring, exasperating, frustrating character.
The arc moves through stages, a plausible sequence of change-inducing events--read the article on 'logical progression'--and each event must be evenly and rationally connected through smooth and believable transitions.
Transitions are a blend of action and narrative that move the story along efficiently from one significant scene to the next, hopping over the non-essential, the superfluous and gratuitous: details that the reader can safely assume, or simply not care about. How often have you wished that life could be that way: hopping over the tedious, the boring, the routine, and leaping from one exciting moment to the next? Well, life is not that way, but a good story has to be.
Resolving the arc of the character or the story is essential. This also is not necessarily how real life is, but how stories must be: the conclusion must satisfy, must arrive at an ending-place that satisfies. It may not be a happy ending, but it must be a good, solid ending. Just as a symphony ends on a note that, somewhere within us, we recognize as a completion, so must a story.
Loose ends need to be tied off; most, if not all the questions raised in the course of the tale, must be given satisfactory answers. Those that will be further developed in a sequel at least need to arrive at an acceptable plateau.
Cliff-hangers...? Sure, there is a place for those, too--especially useful for stimulating sales for that sequel. It's the forgotten or misplaced little event or minor character who raised a question back in Chapter Seven that needs to be noted and woven with a little deft narrative to a proper finish.
Story and Character Arcs are key to realism of fiction-writing. Understanding this is also key to the creative process, an invaluable tool in a fiction-writer's kit.