The audience in a modern theatre are usually(citation needed) separated from the performers by the proscenium arch, although other types of stage are common.
The price charged for seats in each part of the auditorium (known in the industry as the house) usually varies according to the quality of the view of the stage. The seating areas can include some or all of the following:
Stalls, orchestra or arena: the lower flat area, usually below or at the same level as the stage.
Balconies or galleries: one or more raised seating platforms towards the rear of the auditorium. In larger theatres, multiple levels are stacked vertically above or behind the stalls. The first level is usually called the dress circle or grand circle. The highest platform, or upper circle is sometimes known as the gods, especially in large opera houses, where the seats can be very high and a long distance from the stage.
Boxes: generally placed immediately to the front, side and above the level of the stage. They are often separate rooms with an open viewing area which generally seat only a handful of people. These seats are generally considered the most prestigious of the house. A state box or royal box is sometimes provided for dignitaries.
Seating arrangement: Seating arrangements in an auditorium seating layout (or assembly space) will either be identified as “multiple-aisle” or “continental.” These terms are commonly found in design standards manuals, building codes, and similar architectural reference documents. Each size is unique, with specific guidelines governing row size, row spacing, and exit ways. Basically, a multiple-aisle arrangement will have a maximum of 14-16 chairs per row with access to an aisle-way at both ends. In a continental arrangement, all seats are located in a central section. Here the maximum quantity of chairs per row can greatly exceed the limits established in a multiple-aisle arrangement. In order to compensate for the greater length of rows allowed, building codes will require wider row spacing, wider aisles, and strategically located exit doors. Although it would seem like more space is called for, a continental seating plan is often not any less efficient than a multiple-aisle arrangement. In fact, if it’s carefully planned, a continental arrangement can frequently accommodate more seating within the same space.