
eBooks aren’t new technology, but they’re just now becoming common enough that pretty much everyone has heard of them, even if they’re a long way from actually buying one. As with all emerging technology, however, there is a plethora of providers, products, and formats, all jockeying for position and hoping to become the market leader. For those of you who just want to buy an ebook and read the darn thing, this conglomeration of formats and devices can be a nightmare. We’ll break down the terminology and review the currently available formats, so you can better understand the differences.
Definitions
An
ebook is any work of fiction or non-fiction that can be downloaded or delivered to you in a
permanent digital format. You should be able to save it somewhere and read it any time without having to re-connect to the internet. If the information is only available on a web page to read when you’re online, then it’s not an ebook; it’s web content.
An
ebook reader or
ereader is a physical device whose primary purpose is reading ebooks. Examples include the
Amazon Kindle,
Barnes & Noble Nook, and
Kobo eReader, but there are many others—big names and little knock-offs. It’s important to understand, however, that you don’t need a dedicated ereader to read an ebook. You can read ebooks on a desktop or laptop PC or Mac, a smartphone, a tablet PC, or other device.
There are dozens of
ebook file formats on the market right now, though three formats prevail—PDF, EPUB, and MOBI—making up almost three-quarters of all ebooks, according to a 2010 survey by Smashwords. These file formats are simply different schemes for storing a book’s contents in digital form, just as JPG, GIF, and TIFF are different ways of storing a digital image.
eBook software is the program that tells a device how to display the ebook according to your specifications. Each of these programs has a unique set of features, among which are the ability to adjust font sizes and styles, reflow the text, bookmark locations, highlight passages, or read the book aloud to you. This is analogous to image-manipulation software such as Adobe Photoshop or Corel Paint Shop Pro, which each have their own individual feature set for editing images. The most common ebook reading software is Adobe Reader, which displays PDF files, but only PDF files. The software on the PocketBook Reader, by contrast, can display a dozen different file formats.
The Software-Device Connection
While dedicated ereaders usually come with their own proprietary software, it is important to realize that many ebooks can be displayed on multiple devices,
if you have the right software. For example, many people think that books found in Amazon’s Kindle store can only be read on a Kindle device. Not true. Amazon makes their Kindle software in versions for the PC, iPhone, iPod Touch, BlackBerry, iPad, and Android devices, and the software is a free download for any of these devices. Even if you don’t have one of those, you still may be able to read the book on whatever device you do have by converting between formats with a free file conversion program such as Calibre. The same is true for all the popular ebook readers.
In fact, the only books you
can’t easily port over to other software or devices are those that have been created with DRM—digital rights management.

DRM is copy protection for ebooks, and many of the big-name publishers refuse to produce ebooks without it. The (enormous) downside to DRM, of course, is what I just mentioned: if you have a legally purchased DRM-protected ebook, you cannot use the file in another format or on another type of device. That means if you buy several DRM’d ebooks for your Kindle or Nook, but later decide to switch to Kobo, you are out of luck. You won’t be able to read those books on your new device without breaking the copy protection.
eBook file formats are just different ways of storing the digital content of a book, and ebook software is used to decode that content so it can be displayed according to your preferences on a reader. Digital rights management notwithstanding, with the help of a conversion program, you can read just about any ebook on just about any device.