overwrite edit
In an overwrite edit, one or more source clips overwrite any clips in the primary storyline or a selected storyline, starting at a range selection start point or at the skimmer or playhead position. No clip items are rippled forward, so the duration of your project remains the same.
![An illustration showing a clip overwriting parts of two other clips](https://help.apple.com/assets/64FFB258AE78C91D760CB66A/64FFB25D3DC7043983057480/en_US/1a3abd5b5c149f5a388c58d195279b68.png)
Overwriting is purely duration-based and works on range selections only, irrespective of clip boundaries.