SEVEN POINT STRUCTURE
My favorite description of this structure model is from a Youtube video series of a conference presentation by author Dan Wells.
One of the main jobs of the opening of a story is to convince the reader to keep reading. The Hook introduces the beginning state of the main character and the story world and shows what the character has to gain or lose. It also plants at least one question that the reader will yearn to have answered, or creates an "itch" that the reader wants to have "scratched."
2. FIRST PLOT TURN
This is where everything changes. The change might be spectacular, or it might be just a subtle shift, but from here out, everything will be different. The main conflict and oppositional force are introduced here, but may not yet be fully revealed. The characters begin to react to the new reality, often by pulling back, denying the situation, or running away.
3. FIRST PINCH POINT
The first "pinch" occurs about half way between the first plot turn and the midpoint. It puts pressure (thus the term "pinch") on the main character, pushing him or her toward the midpoint change, and reminds the reader of the nature and ramifications of the oppositional force. The stakes are raised.
At the midpoint, an event or epiphany occurs that shifts the context of the story. This is the tipping point that causes the main character to stop merely reacting to the oppositional force and instead begin to go on the offensive. Armed with a new understanding, a new plan, new allies, weapons, etc., the main character begins proactively moving from the beginning state of the story toward the ending state. (For example, from weakness to strength, from slavery to freedom, from ignorance to understanding, from antipathy to love, etc. )
5. SECOND PINCH POINT
This pinch applies even more pressure. It raises the stakes. Makes the main character's situation even worse. The plan fails, the mentors die, companions are lost, and everything goes wrong. The second pinch point is the "jaws of defeat" from which victory must be snatched.
6. SECOND PLOT TURN
The second plot turn is the catalyst that moves the story from the midpoint toward the final resolution. The main character acquires the last "piece" needed to win--which might be an actual object, such as a weapon or tool, or it might be something less literal such as information, a new skill, or an increase in self-confidence. Hope is rekindled, resolve is increased, and the main character flings himself once more into the fray.
The hero wins the day! Victory is snatched from the jaws of defeat! Or conversely, the hero suffers permanent defeat. Either way, the conflict is resolved, the loose ends are tied up, and life resumes in its new form.