Final answer:
A Ripple Edit allows for the seamless insertion of new material into a video timeline, automatically moving subsequent clips to accommodate the new material without leaving any gaps.
Step-by-step explanation:
The method of editing in the timeline that allows for seamless insertion of new material is known as Ripple Edit. A Ripple Edit is used when you want to insert a clip into a sequence without leaving any gaps. If there are any clips following the insertion point, they will move further down the timeline to accommodate the new clip. This avoids the need to manually close gaps, which would be necessary with a simple Cut and Paste method. An Overwrite Edit replaces content at the chosen location but does not move adjacent clips, potentially leading to a disruption of the sequence. A Split Edit, also known as a J-cut or L-cut, is a technique where audio and video transitions happen at different times and is not related to the seamless insertion of clips.