Ripple disbled

I am facing a problem editing and adding two videos to the timeline. When I add a second video track after dragging another video on the timeline. Then the first video cuted into two parts. So how to delete or disable ripple? Or How to solve this problem.

With the right mouse click you can do ripple delete!
With selecting the section and deleting it with the key <del> a free space is left after the deletion in the timeline!

It is right in front of you on the timeline toolbar. Hold the mouse over icons to get tooltips. Or, use Help > Actions and Shortcut > Search. Double-clicking a search result triggers it but does not close the dialog. So, check the toolbar. See also in the menu Settings > Timeline.