Before delving further into the view modes, let’s pause to check out another important feature of Scrivener. The chances are that from time to time you are going to want to split the editor so that you can view two parts of the same document, or two entirely different documents, alongside one another. So let’s do that now. Go to View > Layout > Split Horizontally. Alternatively, click on the button in the right of the header view above (the square with the horizontal line through its middle):

Suddenly, this document is displayed in two panes, which is great when you need to refer back to an earlier place in the file, but don’t want to lose the ability to keep typing in the current location. Note that through the Layout menu, you can also choose a Vertical Split, No Split to get rid of the split altogether, or to hide the header and footer views for the current document view.
All well and good, but we don’t want to be limited to viewing only one document at a time, do we? We can do that in any word processor worth its salt (whatever that means), after all. And naturally, we’re not. Click on any document in the binder, and it will be shown in the editor that currently has the focus. You can tell which editor currently has the focus because when there is a split, the header bar of the focused editor turns blue.
In the binder, click “ThisIsBuzzAldrin” from inside the “Research” folder. “ThisIsBuzzAldrin” is an audio file, so you won’t see much other than a media control bar in the lower part of the top pane (actually, that audio file is the beginning of the coolest phone message I ever picked up; sadly, the message was not for me).
Now you can play the audio file in the top pane whilst typing in this bottom pane. You can control the media file using the keyboard shortcuts defined in the View > Media menu. Ctrl+Enter will play or pause the file, for instance—without you having to click outside of this text. These shortcuts are very useful for transcription work, or for referring to a video file while writing. 
But of course, you can use the split view to view any two documents in Scrivener alongside one another. The snazziness of this feature should immediately be apparent: you can refer to another text, PDF, image or QuickTime document in one view while typing in another. You could hide the toolbar, the header and footer views and the binder and just have the two documents side-by-side while you work.

Make sure this bottom pane has the focus (click in it if you are not sure) so that its header view is blue, and click on “Step 9” so that it opens here.