What action does the Add Edit function perform?

The Add Edit function in AVID Media Composer is primarily used to create a cut point in a clip or a segment in the timeline. When this function is activated, it will "cut" or "split" the segment at the point where the playhead is located, thereby allowing the editor to work with multiple segments more flexibly. This is crucial when making precise edits to a sequence, as it gives the ability to separate clips for rearrangement, deletion, or other editing actions.

The other options do not accurately describe the primary function of the Add Edit. Joining segments or copying would require different tools or commands. Understanding the Add Edit function is key in the editing workflow, as it allows for non-destructive editing and greater control over the timeline.