The 'traditional' Language Laboratory system generally comprises a master console (teacher position) which is electrically connected to a number of rows of student booths (US: carrels), typically containing a student tape recorder and headset with a boom arm microphone.
The teacher console is usually fitted with master playback source equipment (tape recorder), some means of monitoring of each booth in the class via the teacher headset and an intercom facility offering 2-way communication between teacher and student.
All but the most simple or first generation Language Laboratory allow the teacher to remotely control the tape transport controls of the student booths (record, stop, rewind etc.) from the master desk. This allows for easy distribution of the master programme material, which is often copied at high speed onto the student positions for later use by the students at their own pace.
Better tape laboratories housed the tape machine behind a protective plate (leaving only a control panel accessible to the students) or locked the cassette door. This kept the expensive and sensitive decks free from student misuse and dust etc.