The main floor of the theater is called the Orchestra. In some theaters the balconies have special names like Loge, or Founders' Circle, or Dress Circle. Sometimes the front part of a balcony has one name, and the back part of the same balcony has another name. These names, and what they mean, are different in every theater.
Boxes are small booths for a few people, usually located in one of the lower balconies.
Boxes often have extra privacy. Not all theaters have them. Standing room . In some theaters, you can buy a cheaper ticket that entitles you to stand in the back, behind the last row of seats. If you're hardy, this can be a great way to see operas.