Formats & DRM: What does it all mean?

One of the greatest areas of confusion when it comes to eBooks and eReaders is the various formats that are available.  EReaders are capable of handling a wide variety of formats, but generally attention is focused on three different formats: Adobe's Portable Document Format or PDF, ePub, and Amazon's AZW or Mobi format.


ePub was designed to be a reflowable content format, which means that the positioning of the text and images in the document will shift to better match the display it is being read on.  The advantages with this is that it allows content to be read on a wide variety of devices with different displays and different text sizes.  In addition, ePub works as a container format, so it is able to hold the metadata information about the package and content. ePub is widely recognized as being the standard for electronic books, and many of the devices available on the market, including the Barnes & Noble nooks and Sony eReaders, can read this format.  Since this is a widely recognized format, many of the eBook vendors have begun offering lendable eBooks using this format.

A disadvantage to the ePub format is due to its flowing and scalable nature, it makes it inappropriate to use for any content that requires a strict layout, such as art books, comic books, or some poetry. 

Therefore ePub is a good format for textual documents, like monographs, that do not require extensive formatting.

AZW or Mobi:

You may have noticed the absence of the Kindle as a device that uses the ePub format above.  The reason for that is very simple, it does not.  Instead, Amazon uses their own proprietary format, AZW, but also recognizes the Mobi format.  This means that the lendable eBooks available from many vendors are not able to be loaded onto the Kindle.  Like the ePub format, AZW & Mobi are flexible formats that reflow to fit on whatever device they are on.  Therefore, they have the same advantages and disadvantages as ePub.


Adobe's Portable Document Format has been the king of digital textual content for almost two decades now.  Its advantages lie in the fact that due to its extremely widespread use and ready availability of Adobe's "Reader" software, almost everyone can read a PDF file on almost any platform.  This makes this a very attractive format due to its accessibility.  In addition, PDFs preserve the formatting of the original document in digital format, so there is a close correlation to the versions either on screen and on paper.

There are negatives to the PDF format though.  The first is that it is a proprietary format controlled by the Adobe company.  This mean that while it is very easy and cheap to read a PDF file, actually creating and editing them is very difficult and can be expensive.  In recent years, options have become available that have made working with PDF files easier, but usually they do not have the full range of options that are available in Adobe's Acrobat software or in a word processor.  Also, since PDFs closely mimic the original print layout, this makes them complicated to use on many of the eReaders that are available on the market today.  Since the layout in PDFs is fixed, this limits their ability for the text to flow on the eReader screens depending on different user options like text size.   The eReaders are capable of displaying the PDFs, but it often requires a good deal of zooming and panning around to comfortably read the content.

Therefore PDF is a good format for maintaining the layout of a document digitally so that it can be easily printed or viewed on a computer screen.  However, it is not a good format to use for students or faculty with eReaders.

Digital Rights Management (DRM):

As our world becomes increasingly digitial, one of the major fears of content creators and license holders is that it has become easier to copy and distribute the content, with little recognition given to the original creators.  The salve to this fear is Digital Rights Management or DRM.  Imagine DRM as being a sort of digital lock on the content to prevent it from being copied, given to someone else, printed, or some combination.  Usually, DRM schemes require some form of authentication that ensures that the person attempting to access the content has the privilege of doing so.  In many ways, it is similar to the already familiar authentication needed to provide off campus access to library resources.

It may seem that DRM is a good thing, since it protects the content from being copied and distributed beyond the control of copyright, but in many cases it offers difficult complications and reduce the accessibility of the content.  In the case of eReaders and eBooks, DRM is often used to impose artificial limits on the use of the electronic content to mimic the print experience.