Export As
  Export the document in PDF or EPUB formats.
  
Saves the current file to Portable Document Format (PDF) version 1.4. A PDF file can be viewed and printed on any platform with the original formatting intact, provided that supporting software is installed.
 
Export Directly as PDF
  Export the entire document using your default PDF settings.
  
Export the current file to EPUB.
EPUB is standard for electronic book files with the extension .epub that can be downloaded and read on devices like smartphones, tablets, computers, or e-readers.
 
Export Directly as EPUB
  Export the entire document using your default EPUB settings.