A theater, theatre or playhouse, is a structure where theatrical works or plays are performed or other performances such as musical concerts may be produced. While a theater is not required for performance (as in environmental theater or street theater), a theater serves to define the performance and audience spaces. The facility is traditionally organized to provide support areas for performers, the technical crew and the audience members.
There are as many types of theaters as there are types of performance. Theaters may be built specifically for a certain types of productions, they may serve for more general performance needs or they may be adapted or converted for use as a theater. They may range from open-air amphitheaters to ornate, cathedral-like structures to simple, undecorated rooms or black box theaters. Some theaters may have a fixed acting area (in most theaters this is known as the stage), while some theaters such as black box theaters, may not, allowing the director and designers to construct an acting area suitable for the production.
In Australia and New Zealand a small and simple theater, particularly one contained within a larger venue, is called a theatrette. The word originated in 1920s London, for a small-scale music venue.
On and off stage
The most important of these areas is the acting space generally known as the stage. In some theaters, specifically proscenium theaters, arena theaters and amphitheaters, this area is permanent part of the structure. In a blackbox theater the acting area is undefined so that each theater may adapt specifically to a production.
In addition to these acting spaces, there may be offstage spaces as well. These include wings on either side of a proscenium stage (called "backstage" or "offstage") where props, sets and scenery may be stored as well as a place for actors awaiting an entrance. A Prompter's box may be found backstage. In an amphitheater, an area behind the stage may be designated for such uses while a blackbox theater may have spaces outside of the actual theater designated for such uses.