Timeline, clip, sequence, playhead, trim
The editing vocabulary first: the timeline holds clips in order; a sequence is one arrangement on it; the playhead marks the current frame; trimming moves the start or end of a clip without disturbing what sits next to it.
- Timeline: the ordered strip of clips that becomes the video
- Sequence: one arrangement on the timeline, ready to render
- Playhead: the line marking the frame you are on
- Ripple and roll: trims that shift, or leave, surrounding clips
