In theatre and performing arts, the stage (sometimes referred to as the deck in stagecraft) is a designated space for the performance of productions. The stage serves as a space for actors or performers and a focal point (the screen in cinema theaters) for the audience. As an architectural feature, the stage may consist of a platform (often raised) or series of platforms. In some cases, these may be temporary or adjustable but in theaters and other buildings devoted to such productions, the stage is often a permanent feature. There are several types of stages that vary as to the usage and the relation of the audience to them. The most common form found in the West is the proscenium stage. In this type, the audience is located on one side of the stage with the remaining sides hidden and used by the performers and technicians. Thrust stages may be similar to proscenium stages but with a platform or performance area that extends into the audience space so that the audience is located on three sides. In theatre in the round, the audience is located on all four sides of the stage. The fourth type of stage incorporates created and found stages which may be constructed specifically for a performance or may involve a space that is adapted as a stage. Types of staging Proscenium stage Since the Italian Renaissance, the most common stage used in the West has been the proscenium stage which may also be referred to as a picture frame stage. The primary feature is a large opening known as the proscenium arch through which the audience views the performance. The audience directly faces the stage—which is typically raised several feet above front row audience level—and views only one side of the scene. This one side is commonly known as the invisible fourth wall of the scene. The proscenium arch evolved from the in Ancient Greek theaters. This was the space in front of the skênê or backdrop where the actors actually played. The first indoor theatres were created in French tennis courts and Italian Renaissance palaces where the newly embraced principles of perspective allowed designers to create stunning vistas with buildings and trees decreasing in size toward a "vanishing point" on the horizon. Stage floors were raked upward slightly from front to back in order to contribute to the perspective illusion and also to make actors