The print preview allows you to view the printout before you actually print it on paper. The print preview is interactive in the fact that you can zoom in and out, and in some cases, move, delete, and rotate patches.
Zoom Out only works if you’ve zoomed in one or more times. Zoom Out returns you to the previous view.
For example, say you zoomed in on the preview, then zoomed in a little closer to get a better look. If you hit Zoom Out, it will take you back to your first zoom distance.
Fit to Screen returns you to the 100% view of your preview.