Narration and Breaking the 4th Wall...

Narration

Narration is most commonly used in a film to show an older version of the main character narrating his life as the audience is watching. Some classic examples of this would be Kevin Spacey's character in 'American Beauty', Morgan Freeman in 'The Shawshank Redemption' and Tom Hanks as 'Forrest Gump'. If the narration is done properly, it can be very effective in engaging the viewer and causing them to grow attached to the main character because they can relate to them more.

(Kevin Spacey in 'American Beauty')

Narration has always been popular and widely used in cinema- from the early classics in the 60's and 70's to more recent blockbusters, such as Rene Zelwegger in 'Bridget Jones' Diary', Kristen Stewart in 'The Twilight Saga' and even Simon Bird as Will from 'The Inbetweeners Movie'. These examples however don't follow the classic structure of a character narrating his/her past, but instead, for instance in the case of Bridget Jones, they are narrating things as they happen- she is reading from her diary entries as she is writing them, making the viewer feel like they are also reading from her diary. In 'The Inbetweeners Movie' Will is not an old character speaking about his past, instead, just like in the show, he is guiding the audience through the failures of his life as they happen.

Breaking the 4th Wall

'Breaking the 4th Wall' is a term first introduced in 19th Century theatre, which describes a boundary or 'wall' between the play and the audience that seperates fiction from reality. Breaking this wall became commonly used to try and engage the audience more with the character that is breaking it and let them be more of a part of it. This would be done by talking to the audience as if no one on the stage could hear or see them. This is now almost always used in pantomimes and many other theatre productions. This method then went through a transition from the stage to the screen. Now, many films use breaking the 4th wall to form the attachment between the character and the viewer. This form is most commonly used in comedy films, such as 'Waynes World' and perhaps most famously, 'Ferris Bueller's day off'. 

('Ferris Bueller's Day Off'-Opening Monologue) 

-KW