What is Bertolt Brecht's Verfremdungseffekt (Distancing Effect) ?

Something important to remember when considering Brecht's techniques for making theatre, is that he was an advocate for communism as a result of the horrors he witnessed in WW1 in Germany serving as a medical orderly. He was responsible for creating a kind of theatre that challenged Facist ideals that he believed were embedded in certain kinds of traditional theatre. According to Brecht, the problem with what he called 'dramatic' theatre is that it creates an illusion of a world that allows the audience to consume the ideals of the writer without any disruption. Therefore, he used techniques to create the Verfremdungseffekt (distancing effect), with the aim to reveal the mechanisms behind theatre's illusion in order to break it. For example, having the actors sit on chairs on stage watching the action during scenes their characters aren't in, break the fourth wall or wear placards on which their character's function is written (ie. The Villain).