In order for a theater event to occur, there must be a place where an audience and performers come together: a theater space. This theater space must include a defined area for the actors to perform, an adjoining space for the audience to sit or stand, and usually a place for the performers to exit, enter, and change costumes.

While theater spaces have been created in a variety of shapes, sizes, and locations, they have usually taken one of four forms: proscenium, thrust, arena, or created, or "found," space. Each of these forms has its advantages and disadvantages, its own atmosphere, and its own production requirements.

Usually, only one type of theater space has been prevalent at a particular historical period. However, in the modern era all four of the forms exist simultaneously.