The Media bin is where the content (slides, images, video clips) can be stored.
Note: Any item must be added to your media bin before it can be added to your timeline.
In this case, an image of the library homepage ("Homepage") and a screen recording ("Rec 6-15-2020") have been added to the bin. Items can be dragged into the media bin or imported using the File menu. Once there, they can be dragged directly on to your timeline, as "Homepage has been done with below.