The imaginary "wall" is at the front of the stage in a traditional three-walled set in a proscenium theatre, through which the audience sees the action in the play. The idea of the fourth wall spread in 19th-century theatre with the advent of theatrical realism. Playwrights, filmmakers and authors alike "break the fourth wall."
When characters break the "Fifth Wall," it shows they have knowledge of other fictional characters from another, unrelated actuality.
Breaking the fourth wall is observed sometimes in literature, where a character directly addresses the reader.
Some characters have been known to 'break the fourth wall' by speaking to, or about, the audience. Not only do they talk to the reader, but they (usually) know that they are fictional creations in a story. On occasion, this may be a vehicle for dramatic irony. The fourth wall can also be reinforced by a character saying that, i.e., 'this isn't a movie, you know'.
Characters continually "reach out" to their audiences and bring back aspects of the audience's world to the stage. That is, "Open address,'" or what has been called "extradramatic" or "illusionbreaking" speech, is for Hill an essential component of theatrical meaning, part of a dramatic strategy that "challenges.., playgoers, asking] for answers lying outside the stage, in the playgoer/playhouse world."
In today’s theater and film, we talk all the time about the actor becoming the character; here, we have the character becoming the actor.
Breaking the fourth wall is easy: Just speak directly to the audience or look directly into the camera. Certain material calls for this practice — Pseudolous, Ferris Bueller, and Bernie Mac do it all the time. But when it's not a part of the show — when actors get distracted and are forced to stop the natural flow of the story — performers and viewers alike usually need a moment to adjust and get back into it. Cell phones in the theatre are the biggest culprits these days.
In the illusionist tradition that dominates American theatre practice, performers and spectators are separated by a curtain of light that helps maintain the fictitious fourth wall. Performers facing the audience are blinded by the workings of the apparatus that frames them. . . .
In the theatre, fourth wall staging requires a suspension of disbelief because the space of the stage is contiguous with that of the audience, however much the proscenium arch serves as a demarcation between the two spaces. With the screen image, belief is more easily given because the image represents a truly unbridgeable space, a space that seems to belong to the real world, yet one that we can never access.
Building the fourth wall can be challenging, but when it's done properly, it makes the theatre, TV, and film experience both believable and magical.
The idea is that the stage background is constructed with a cutaway view of the house, so that the people sitting on the audience can look through this invisible 'fourth wall' and look directly into the events inside. Such stages preclude theater-in-the-round and they require a modified apron stage with an expensive reproduction of an entire house or building, often complete with stairs, wallpaper, furniture, and other bits to add verisimilitude. This type of stage became increasingly common within the last two centuries, but the money involved in constructing such stages often precludes their use in drama, leaving arena stages most popular for the architectural design of the stage.
In theater, the fourth wall is that invisible forcefield around the stage that keeps actors in their own little world, and separate from the audience. Actors on stage—and even on screen (we're looking at you, Jim Halpert)—sometimes break the fourth wall for dramatic (or comedic) effect, and directly address the audience. The fourth wall didn't really develop in the theater until the late 18th and 19th century.
The concept of the "fourth wall" appears in critical writings about the theater at least as early as 1758, when Denis Diderot, one of the Encyclopedists, wrote, "When you write or act, think no more of the audience than if it had never existed. Imagine a huge wall across the front of the stage, separating you from the audience, and behave exactly as if the curtain had never risen."