Dream sequences

As our film is set up around this dream that is seen at the begginging of the film i have decided that today I'm going to talk about dream sequences and how there used alot in television and film.

Description

The Dream Sequence is a fragment that is separated from the rest of the story and which explains something that would be difficult to include in the main storyline.
It may appear as in such forms as a flashback, vision or daydream, and may be visually distinguished by fogging, music or other marking that emphasizes that this is not a 'real' part of the story.
Dream sequences are often quite short.

Example

A woman meets a man and has a dream sequence of him seducing her.

A scene shows the hero doing battle with the villain and losing. It turns out to be a nightmare he is having.

Discussion

The daydream can be used as a way of explaining what a person is thinking, and thus acts as a form of visual 'thought bubble'.
Dream sequences can be used to add humor, for example with morphing to exaggerate emotions. They may also be used to add tension in showing possibilities.
The dream sequence can also be used as a 'cheating' device for authors who want to explain something and do not know how to explain it in the story.

(source-http://changingminds.org/disciplines/storytelling/devices/dream_sequence.htm)

A dream that is used can also forshadow what may happen in the upcoming future on the screen, and although its unlikely for the exact same thing to happen, its possible to show something that may be seen as impossible at the begining to then come true later on.