The Single Frame View replaces the grid of frames in the storyboard frame view with a view of the current frame only. This can be useful if you need more room outside the frame to grab handles or to start drawing strokes.
You can also use it simply to reduce visual clutter, so you can concentrate on one frame at a time.
You can enter Single Frame View with the View > Single Frame command, by double-clicking a frame handle in the Storyboard View, with the View > Zoom to Fit Frame command, or by clicking on the view's tab. Pressing Esc returns to Storyboard View.
The View > Scroll Current Frame and View > Lock Frame Position commands