(covers information from several alternate timelines)
A bridge simulator was a device used at Starfleet Academy's Starfleet Training Command for training cadets in navigation and starship handling. The bridge mock-up was based on then-current bridge designs. Simulations were monitored from a room adjacent to the simulator. Exercises were programmed into the simulator computer by personnel assigned to the Academy, and the cadets were put through their paces using these exercises. One of the exercises performed in the simulator was the Kobayashi Maru scenario. Simulations were monitored by technicians and observed by officers from a room adjacent to the simulator. After an exercise, the cadets' performance was reviewed in a briefing room. (Star Trek II: The Wrath of Khan; Star Trek)
The simulator was rigged with pyrotechnics in order to realistically simulate battle conditions. As a result of the pyrotechnics, the simulator frequently required maintenance. Smoking was prohibited in the simulator. (Star Trek II: The Wrath of Khan)
With the advent of holographic technology, physical simulators fell out of use as similar conditions could be reproduced on holodecks. (VOY: "Learning Curve", PRO: "Kobayashi")