Recognition and Revelation

Revelation occurs when key information is revealed to the audience but NOT to a character, creating both dramatic irony and tension.

For example, in Hitchcock's North By North West,  we, the audience, see the CIA reveal that the mystery man, Kaplan, doesn’t exist. However, the main character, Thornhill, played by Cary Grant, doesn’t know this and spends the entire second act looking for Kaplan (irony.) What he doesn't know might get him killed, and we are on the edge of our seats hoping he figures it out before it is too late. (tension.)

Recognition occurs when key information that the audience knows is finally revealed to a character. This often resolves tension and dramatic irony.

For example, in Hitchcock's North By North West, the tension of the second act is resolved when Thornhill is told Kaplan does not exist. However, a new tension is established with a Reveal, both he and the audience discover that Eve is working for the CIA and that Thornhill has unwittingly put her in grave danger.

Definition of Screenwriting

In the 21st Century, screenwriting should be defined as writing scripts for moving pictures that appear on any screen.

This includes traditional movies projected in theaters, but also television, animation, webisodes, and other fictional, narrative "moving pictures" that appear on computer screens, smartphone screens, virtual reality goggles, holograms, other technologies.

Tension

There are many forms of tension in movies, but tension always creates anticipation and anxiety about what is going to happen next. Tension is what makes you turn the page. Tension keeps the audience in their seats.

Tension is created when the audience can imagine and anticipate what might happen next in the story, sequence, or scene, but isn't sure which way it will go. The story elements suggest several possible futures. 

We (the audience) HOPE for one outcome(s), but we FEAR another.

More specific forms of tension include dramatic tension, comic tension, romantic tension, suspense/fear tension, and more generally dramatic tension. In all cases, the writer leads the reader/audience to imagine something funny, romantic, or scary is about to happen next.

More importantly, while we can imagine (hope) for a good outcome we can also imagine (fear) a bad outcome, and it is not clear to us which way it's going to go.

In general, tension rises (i.e. the stake rise) when the possible good outcome gets better and/or the possible bad outcome gets worse. Likewise, if we have no sense of the future or if we feel like we know how things will turn out, the tension dissolves. To engage the audience, we must keep the tension high.