There was a time several years ago - during the great battle for ebook formats - when PDF was one of the formats contending to be the ebook format. Software companies like Microsoft were competing with PDF to become the dominant ebook file format. Microsoft had its Microsoft Reader software which followed the Open eBook Publication Structure (OEB), which was based on HTML and XML. The great battle ended with the OEBF format, the precursor to ePub, emerged as the standard thanks to book industry support. The standard format for ebooks today is the ePub format.

Adobe develops software for creating PDF files and the main software package for development is the Adobe Acrobat software. PDF became a popular format from its use with government files, including tax forms. The popularity of Adobe software means there is always a need to convert from PDF to ePub and vice versa. The ePub format is very useful if you want to read a document on an ebook reader or other device that cannot read a PDF file. However, Adobe products do not provide this conversion. You have to use a third party tool.

You can find free online tools to convert ebook files to PDF. A search for "free PDF to ePub" or "free ePub to PDF" will bring up multiple free online tools. The downside is that this will require uploading files to the Internet and downloading the converted files from the Internet. While some of these services are frequently used and probably safe, using them does raise malware and virus risks. It also raises privacy risks, especially if the file is a document you created yourself.

Here are some articles about some other tools you can use to convert these documents:

• The Calibre ebook management software can convert to PDF. An How-To Geek article walks you through the process and explains how to optimize converting PDF files using K2pdfopt.
  
  
• A Lifehacker article explains how to use Calibre to convert a file to the ePub format where it can be read with Apple's iBooks software.
  
  
• An article from Digital Trends suggests Calibre, an online tools and an Android app called EPUBator for your PDF and ePub conversions.