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Finding E-Books and Audiobooks: Understanding E-Book Formats

E-Book Formats

  • DRM - Digital Rights Management: Technology that limits the use and duplication of copyrighted works. DRM may limit the number of times a file may be read, watched, or listened to; what type and number of devices the file may be used on, and whether or not a full or partial copy can be made of the file.
  • Open Standard - file format that can be used by any company without paying royalties or liscensing fees.
  • Proprietary - files format that can only be used by the creating company (example: Kindle), or, if that company permits, by third parties that have purchased a usage license. 
  • EPUB: an open-standard file format for digital books and one of the most widely supported along with .pdf and .txt.  An EPUB benefit is that it allows a books text to automatically adjust or 'reflow' to different screen sizes, including smart phones, netbooks, and ereader devices.  EPUB ebooks also support embedded content, allowing, for instance, a Flash video to be embedded within an ebook.
  • PDF or portable document format, is an open standard file format created by Adobe Systems that can be read by most computers and is supported by most ebook readers. Like EPUB, it can display images. However, unlike EPUB, it does not support word-wrap around images.   
  • Plain Text (.txt).  The "lowest common denominator" of open standard text files.  It can be read by virtually all computers and most ebook readers but does not support images or digital rights management making it a poor choice for publishers who wish to block users from making unauthorized copies of their works.
  • Kindle (.azw).  The Kindle proprietary file format can only be read by Amazon's Kindle devices.  However, software is available to read the Kindle format on virtually any other device including PC's, iPhones, iPad's, etc.
  • eReader.  eReader is a proprietary file format created by PalmMedia.  The eReader format is used in conjunction with the EPUB format by Barnes & Noble's online ebook store for use with the Nook ebook reader.  Software is also available to view eReader formatted books on most other devices/computers.  
  • BBeb.  Short for Broad Band eBook, the BBeB proprietary file format was created by Sony and Canon for Sony ebook readers. 
  • lrf.   LRF, LRS, LRX are Sony's proprietary formats. They have been superseded by Sony's acceptance of epub as the default format in their book store.  
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