Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online.A theatrical technician, tech, techie, theatre tech or theatre technician is a person who operates technical equipment and systems in Performing arts and Entertainment industry. In contrast to performers, this broad category contains all "unseen" theatrical personnel responsible for the logistic and production-related aspects of a performance, including designers, operators, and supervisors.A single theatrical technician may regularly do one or more of the above jobs during load in, load outs, rehearsal and performance. Performance technicians are generally divided between those backstage (stagehands, Stage Managers) and those in a control room (lighting and audio technicians). During load in and load out additional crew members may be needed due to the amount of work required to be completed in a short time span. Larger and more complex shows require larger crews and often personnel with specialized advanced skills to perform these job functions.