Breaking the Fourth Wall

When we talk about the 'Fourth Wall' often theatre is brought to mind, however it is also used in the film and television industry aswell.
Breaking the fourth wall is where the characters acknowledge their fictionality, they do this by addressing the audience. When this is done in film its often used to draw the audience in, this is often risky, as it could look cheep, or cheesy. However in some cases it works perfectly. It gives the audience a bigger insite into the story world and makes them relate to the character.