Many different types of e-book readers are available, and each device has its pros and cons. E-book files likewise come in many different formats and no reader can handle them all. The Kindle supports a large number of existing formats, either natively or with conversion. A few file formats require the use of special software to be compatible with the Kindle.
AZW: The Primary Format
The "AZW" format is used for e-books that you buy at Amazon's Kindle Store. It is the preferred format to ensure maximum readability on the device. The format is proprietary and is actually a variant of the MOBI format, originally created by French company Mobipocket. Amazon purchased Mobipocket and adapted the format for use on the Kindle.
Other Native Formats
The Kindle can display some other e-book formats natively, which means these files can be loaded directly onto the device and read in the same manner as an AZW file. MOBI files and PRC files (a format used on the Palm) can be read if they do not contain Digital Rights Management (DRM) protection. DRM typically limits a book to a single reading device. In addition, the Kindle can handle plain text files (TXT) and Adobe's PDF format, although not all PDFs display well on the Kindle.
Available Through Conversion
Conversion typically involves sending a file to your Kindle email address. Amazon says it can convert HTML, DOC (a Microsoft Word file) and the graphic file formats JPEG, GIF, PNG and BMP. Some people are now using the Kindle to read scanned manga comics; a program called Mangle allows you to convert manga if scanned to one of the graphic file formats supported on the Kindle.
The Kindle can play audio files. Music files saved in MP3 format are compatible and so are audio books from Audible.com, which is also owned by Amazon. These files are in Audible (AA) and Audible Enhanced (AAX) formats.
The most widely used format that is not supported on the Kindle is the EPUB open source format, used by many other e-readers such as the Nook from Barnes and Noble. Amazon may eventually add EPUB compatibility to the Kindle; in the meantime, free programs such as Calibre can be used to convert e-books from EPUB to AZW format. Other formats such as LIT (MS Reader) and LRF (a Sony format) can be converted this way as well. The success of these conversions can be hit and miss but they are options available to Kindle users.
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