What is the most common term used for the left monitor in video editing software?

In video editing software, the left monitor is most commonly referred to as the "Source." This area is where editors preview the clips, sequences, or media files that they plan to use in their project. The Source monitor allows users to review footage, set in and out points, and make initial adjustments before inserting it into the timeline for editing.

By focusing on the source material, editors can ensure they are selecting the right clips and making necessary edits before bringing them into the main timeline, where the actual record or final output is assembled. The terminology used in editing software can vary somewhat, but "Source" is a widely recognized term that aligns with standard practices in the industry.

The other terms, like Record, Track, and Output, refer to different components of the editing process and do not specifically identify the left monitor's function in most video editing environments.