A box office or ticket office is a place where tickets are sold to the public for admission to an event. Patrons can perform the transaction at a countertop, through a hole in a wall or window, or at a wicket. By extension, the term is frequently used, especially in the context of the film industry, as a metonym for the amount of business a particular production, such as a film or theatre show, receives. The term is also used to refer to a ticket office at an arena or a stadium.
Etymology
Ceramic money boxes were used at the sixteenth-century Globe Theatre and Rose Theatre in London, where many examples have been found during archaeological investigations. They were possibly used by the "gatherer" at the entrance to the theatres, who collected the admission money. There is disagreement, however, around whether the term originates from this time, as the objects could have been carried by the many snack-sellers attending the audiences; they too needed a convenient and secure way to collect their customers' cash.
There is no record of the term "box office" being used until the eighteenth century: it was being used from at least 1741, deriving from the office from which tickets for theatre boxes were sold. This is the derivation favoured by the Oxford English Dictionary.
Related terminology
Total ticket sales were being termed box office from at least 1904.