This is the slide show window. With it, you can view all of your fonts in a continuous display. Or go to different fonts.
The Quick View display gives you a side by side comparison of selected fonts from the main font listing table.

This is the FontCat print preview screen. When you select print, this is the window that is brought up. At first you can see a preview of what the printed output will look like.

You will see buttons to save the print output as a PDF file, or an image file (1 image file per page), and you can selected from several image formats, such as tiff, PICT, png, Photoshop®.

The Layout editor is where you can create customized layouts to handle printing of your fonts or font listing.

Download some sample layouts and resulting PDF files.