The interface of Final Cut Pro X is split into three windows: the Browser, the Viewer, and the Timeline.
The Browser is where you access the media with which you build your edited movie. Here, all the Projects, clips, audio files, graphic elements, and music are filed away for you to access, in Filmstrip view or List view.
You can quickly toggle between Filmstrip view and List view by pressing the controls at the bottom of the Browser.
The Viewer: this ...