1. Recorder: used for recording and playback. There are usually the following buttons:
-Play button: Press this button to start playing the recording.
-Stop button: Press to stop playing.
-Recording button: Press to start recording.
-Stop recording button: Press this button to stop recording and save the recording.
2. Player: used to play listening materials or recordings. There are usually the following buttons:
-Play button: Press it to start playing.
-Pause button: Press this button to pause playback.
-Stop button: Press to stop playing.
-Fast-forward/fast-backward button: used to fast-forward or fast-backward the playback progress.
3. Projector: used to project slides or videos. Usage usually has the following steps:
-Connect the projector to a computer or other device.
-Turn on the projector.
-Turn on the computer or other equipment and transfer the screen content to the projector.
-Adjust the parameters of the projector such as focal length, brightness and contrast to obtain the best projection effect.
In addition to the above instruments, some other devices may be used, such as microphones and headphones. Each school or institution may use different equipment and may use it in different ways. Therefore, if you want to know the specific use of the course instruments, I suggest you consult the relevant teachers or technical support personnel of your school or institution.