Timeline

The timeline is the central workspace of a non-linear editing (NLE) system — a horizontal, time-based interface in which all the video clips, audio clips, graphics, and other elements of a sequence are displayed as horizontal bars arranged in tracks. The horizontal axis represents time (left is earlier, right is later), and the vertical axis shows layers (tracks stacked above and below each other). Clips in the timeline represent when, in the final video, that piece of footage begins and ends. The editor assembles the video by dragging clips from the media browser into the timeline, placing them in sequence, trimming them, rearranging them, and applying effects — all directly within this visual representation.

The timeline is organized into tracks: video tracks (V1, V2, V3...) stacked vertically, with higher tracks composited over lower ones (V2 appears over V1 in the final output), and audio tracks (A1, A2, A3...) that mix together into the final audio output. Multiple video tracks allow compositing: B-roll placed on V2 plays over the primary interview on V1, replacing the view of the interview for the duration of the B-roll clip. Graphics, titles, and motion graphics elements placed on V3 or higher tracks appear on top of all other video. This stacked, layered system is the visual representation of the compositing and audio mixing relationships that produce the final output.

For producers who aren't editors, understanding the timeline as a spatial representation of time clarifies how editing works as a discipline. The question "can you move that part earlier?" translates directly to "can you shift that clip leftward on the timeline?" The question "can we run the voiceover over both of those clips?" translates to "can you extend the audio track on the voiceover so its bar spans both video clips' positions?" The timeline's visual language — horizontal extent equals duration, left-to-right equals chronological order, tracks represent layers — makes the editing process legible to non-editors who understand this basic framework, enabling more precise and productive feedback conversations between producers, clients, and editors.