Diegetic/Non-Diegetic

Link-http://filmsound.org/terminology/diegetic.htm

The link above is where i got this information.

Diegetic is a sound coming for a real object such as a radio or a car engine Diegetic sound is any sound presented as originated from source within the film's world 
Diegetic sound can be either on screen or off screen depending on whatever its source is within the frame or outside the frame. While non-diegetic sounds come from off screen such as;

• narrator's commentary
• sound effects which is added for the dramatic effect
• mood music

Non-diegetic sound is represented as coming from the a source outside story space. 

The distinction between diegetic or non-diegetic sound depends on our understanding of the conventions of film viewing and listening.  We know of that certain sounds are represented as coming from the story world, while others are  represented as coming from outside the space of the story events.  A play with diegetic and non-diegetic conventions can be used to create ambiguity (horror), or to surprise the audience (comedy). 

Green Screen

What is a green screen?

Green Screens are a piece of technology that allows the actors to be in a different location. They do this by making a single colour sheet suspended then this allows all of the sheet that isn't blocked by the actors to be changed to another image such as;Fields, Mountains or a different environment completely.

How does it work?

Companies can only use some software because it won't work with any program.

Name 3 Films that use this effect?

Harry Potter
Avatar
Lord of the Rings

Think of a 1 minute scene that you could make using the green screen?

The Demolish of important land marks and the construction  of new ones


 This image is from Final Destination 4 as you can see they used a green screen to show a destroyed bridge in the finished product.This can also applies to the movie 300 even though that the back drop is blue