This is the stage/setting where actors are able to prepare themselves before entering the front stage.

The area you are referring to is commonly known as the "backstage." In the context of theater and performance, backstage is the part of the stage that is not visible to the audience. It serves as a behind-the-scenes area where actors, performers, and crew can prepare for their performances. This area is crucial for various activities such as costume changes, makeup application, and rehearsing lines. Backstage typically includes dressing rooms, green rooms, and other support spaces that help facilitate the smooth operation of a performance. It ensures that the actors are ready and prepared before they enter the front stage, where the audience can view the performance.