How do I edit or delete a part of a video/audio?

To edit a particular part of a video or audio, use the Split feature:

1. On the timeline, tap on the element you wish to edit: video clip / audio track
2. Move the playhead (yellow vertical line) to the point where you want to start editing
3. Tap Split from the editing toolbar
4. Now move the playhead to the point where you want to end editing > Tap Split
5. Tap on the fragment you created > Choose from many actions in the toolbar:
   you can Delete it or change its Volume, Speed, etc.