title_body: What are the different file formats that eBooks are available in and which of these is most widely supported? I am a beginner to eBooks, and as somebody who has been "outside" of eBooks I've only ever heard of Amazon's Kindle and seen a variety of options for purchase on Google Play.
  
  I have recently purchased an Android tablet. If I were to start buying my reading material as eBooks but after having a look at the various reader applications available, it seems they all support a different set of file formats.
  
  What are the different file formats that eBooks are available in and which of these is most widely supported?
upvoted_answer: There is an extensive (though maybe not exhaustive) list of ebook formats on Wikipedia. The article does a comparison on the formats.
  
  The most widely supported formats are epub and pdf (and mobi/prc / KF8 / AZW if you include Amazon Kindle). Of course, plain text is probably THE most supported format, but I'm assuming you meant something that supports special formatting etc.