The Video Track Monitor button determines whether you see video during playback. You can turn it off at any time to monitor only audio during editing. When there are multiple video tracks, all tracks below the monitored track are active during playback.

When you edit with multiple tracks, you can activate the monitor on a lower track to monitor only the video on that track. This feature is especially useful when you have multiple layers of video effects and need to see one track without additional layers. You can also monitor a solo track, as described in Monitoring a Solo Track.