Theatre (or theater) is a branch of the performing arts.

While any performance may be considered theatre, as a performing art, it focuses almost exclusively on live performers creating a self contained drama. A performance qualifies as dramatic by creating a representational illusion. By this broad definition, theatre has existed since the dawn of man, as a result of the human tendency for storytelling. Since its inception, theatre has come to take on many forms, utilizing speech, gesture, music, dance, and spectacle, combining the other performing arts, often as well as the visual arts, into a single artistic form.

The word derives from the Ancient Greek theatron (θέατρον) meaning "the seeing place."

Running crew or run crew is a collective term used to describe the members of a technical crew who supervise and operate ("run") the various technical requirements during a performance. The term running crew generally refers to all crew members, excluding performers, on a given production, regardless of their location within the venue, but includes only those present during an actual performance.

Technical crew members (technicians), involved in the initial set-up (load-in) or disassembly (strike) of a production that are not involved in the actual performance are not considered part of the running crew.

This term is typically not applied to crew or department heads, although there are exceptions.

The running crew may also include performers, if they are functioning in technical capacities while offstage.