An American Editor

October 27, 2010

An eBook Primer: Part II

Yesterday’s article, An eBook Primer: Part I, explored ebooks and ereaders in general. Today’s addresses the issue of ebook formats. Today’s article first appeared on Teleread‘s website and was written by a Teleread staffer. The article is reprinted with permission from Teleread and is copyright 2010 by North American Publishing Company, the parent of Teleread. To reprint the article, please contact Teleread.

Future instalments of the “primer” will also be reprinted. I hope you find them valuable and informative.


TeleRead E-book Primer Part Two: Formats

By Chris Meadows

Ebooks_stack_lg You may be old enough to remember a time when there were two different formats of video tape–VHS or Betamax. If not, you’re almost certainly old enough to remember that there were two different competing high-definition DVD formats a couple of years ago–HD-DVD and Blu-Ray.

And you’ll know that in both cases, you had to have the right player to play each format: Beta tapes would only play in Beta players, VHS tapes would only work in VHS.

It’s much the same way with e-books, except that instead of only two competing formats, there are at least a dozen. Fortunately, only three of those really qualify as important enough to worry about right now, or else this article would be a whole lot longer!

 File Format vs. DRM Format

E-books actually have two different types of format: file format and DRM format.

File format is like what we’ve talked about above—the different ways to put e-book files together developed by different companies, kind of like the difference between VHS and Beta. The main e-book file formats I will be talking about today are PDF, MobiPocket/Kindle, and EPUB. Some e-book readers will read only one kind of file format, while others will read several.

DRM format has to do with Digital Rights Management, which is a kind of lock that some companies put on their e-books to prevent buyers from copying them and passing them on for free—or reading them in a competitor’s e-book device.

Not all e-books will have DRM, but most of the ones you buy from big e-book stores such as Amazon or Barnes & Noble do. Some e-book formats can have different forms of DRM applied to them, depending on which store you buy from. (For more information on DRM, see the TeleRead DRM Primer.)

If you want to read an e-book, your e-book reader device or application must be compatible with both the file format and the DRM format of the e-book.

The only e-book readers that can read files in multiple competing file and DRM formats are the iPhone, iPod Touch, and iPad, simply because they can run reader apps from all the different companies.

The interaction of these two different kinds of format, and the restrictions on what kind of readers can read both of them, is what has made the e-book market so complicated for first-time buyers. (It is also why the Kindle is such a popular reader—when Kindle owners buy e-books from Amazon, they just work without all that confusion.) The reason I’m writing these primers is to try to simplify some of that.

There are far, far more e-book reading devices available than just the Kindle, Nook, and Sony. There are readers from brands you’ve never heard of, far far more than I will be able to cover in these primers. If you want to know whether you can read an e-book with your device, you need to find out what formats the e-book is in, and what formats your device can read.

A great place to find out more about e-book formats is the MobileRead wiki’s e-book formats page.

PDF Format

Adobe’s PDF (Portable Document Format) files have been in use for a long, long time. They allow book and document producers to standardize the appearance of printable files, so they can be sure the files will look exactly the same no matter where or how they’re printed out. This is especially useful for paperwork, such as forms that must be filled out.

They are also used for e-books, especially in the role-playing game industry, for the way they can exactly represent the printed page on a computer screen. This is useful for books that have a lot of specific formatting (such as the charts and tables from role-playing games) or otherwise just need to look nice.

While the 8.5″ x 11″ form factor of most PDFs means they’re not ideal for reading on most computer screens, they’re still better than nothing. The form factor also means they often look cramped on smaller e-book reader screens. This is why most e-books are sold in other formats, and if another format is available you would probably be better advised to get it than to get PDF.

Popular e-book readers with some PDF compatibility include the Kindle, the Sony Reader, and the Kobo Reader. Computer programs that read PDFs include Adobe Reader and Adobe Digital Editions (for DRM-protected PDFs). There are also PDF readers for the iPhone and iPad’s iOS, such as GoodReader and Dicebook. Their larger screen size means that PDFs often look best on the iPad or the Kindle DX.


Some PDF files have Adobe’s Adept DRM on them, which means they have to be read on Adobe Digital Editions. Most PDFs are not DRM-protected, however.

MobiPocket/Kindle Format

It might surprise you to know that the super-modern up-to-date Kindle actually uses one of the oldest e-book formats still in continuous use. This format started out as a modification of the PalmDOC format for Palm Reader, to allow HTML-like text emphasis and other tagging. It was used in MobiPocket Reader for the Palm PDA, later expanding to other PDA platforms, until Amazon purchased the company several years ago.

Subsequently, Amazon made some changes to the format and now uses it in the Kindle. The biggest change is that the Kindle uses an entirely new, incompatible DRM scheme from the original MobiPocket DRM (see below).

MobiPocket format is often referred to as PRC or MOBI format based on its file extensions—especially in the tech specs of compatible e-book readers. (It’s actually erroneous to call it PRC, because PRC was a container file format that could have contained any of a number of different Palm database files. However, since almost nobody else uses the original Palm formats anymore, most .PRC files encountered these days will be MobiPocket.) Kindle format is sometimes called AZW.

There are official MobiPocket reader apps for the PC, Palm, Blackberry, and Windows Mobile. DRM-free MobiPocket files can be read by a number of other apps for PC, Apple, or iOS, including Calibre, Stanza, and FBReader. However, there is no app for iOS that can read MobiPocket-encrypted e-books.

The Kindle can read DRM-free MobiPocket books (such as the ones Baen has available on its Free Library and Webscriptions), but not e-books with the original MobiPocket DRM on them. Likewise, DRM-protected Kindle e-books cannot be read on any of the MobiPocket readers, though there are Kindle Reader applications that read Kindle books for a number of different platforms including PC, Android, and iOS.

MobiPocket/Kindle and DRM

The original MobiPocket DRM format was one of the most widely-used formats for selling e-books in the days before the Kindle, on stores such as Fictionwise, eReader, BooksOnBoard,, and others. However, none of these books can be read on the Kindle without first cracking the DRM (which is illegal under current US copyright law).

The Kindle DRM format is used for the Kindle and its related readers. As mentioned above, it can be read by the Kindle and Kindle Reader software, but not by anything else.

EPUB Format

EPUB has come to be considered more or less the “standard” e-book format of the publishing industry. It is the main e-book format currently used by Sony Reader, Adobe’s Nook, Borders’s Kobo Reader, Apple’s iBooks, Adobe Digital Editions, and a number of other reader devices and applications. Most e-books you can buy now (from anyone except Amazon) will come in EPUB format of some kind. About the only e-book device that won’t read EPUB is the Amazon Kindle.

However, even this “standard” has problems; it is saddled with no fewer than three competing DRM formats, meaning that if you bought the e-book from a store that uses DRM, odds are you’ll only be able to read it on devices or programs that work with that particular store.


There are three different DRM formats for use with EPUB:

Adobe Adept is the first DRM format, and the one used by Adobe Digital Editions, Barnes & Noble’s Nook, the Sony Reader, and the Kobo Reader, as well as a number of lesser-known e-book devices.

Barnes & Noble’s Nook/eReader DRM uses the DRM that was originally developed by the eReader e-book store for use on its own special e-book file format (later bought by Barnes & Noble just as MobiPocket was bought by Amazon). As noted above, it can also read titles in Adobe’s Adept DRM.

The iBookstore uses the same Fairplay DRM that Apple used on music and currently uses on movies and iOS applications.

Except that the Nook can also read Adept, e-books sold in each of these DRM formats are entirely incompatible with readers that use the other two formats (though DRM-free EPUB books, such as those sold by Baen, can be read by all three). If you buy a DRM-locked EPUB book from the iBookstore, you can’t read it on the Nook or the Kobo, for example.

Other Formats

The above formats are the main formats currently used by the “top five” e-book devices or applications, and hence the ones you’re most likely to encounter if you buy any well-known e-book device or app: Kindle, Nook, Sony, Kobo, or iPad/iPhone. There are a number of other formats that are still in some limited use, such as eReader or Microsoft Reader (LIT), but it is rare for anyone using one of the major e-book reading devices or apps to encounter them anymore (and this primer is complicated enough already!). At present, PDF, MobiPocket/Amazon, and EPUB are the main ones to worry about.



October 26, 2010

An eBook Primer: Part I

Now that the holiday season is upon us (or shortly will be), some of us will be thinking about buying an ereader as a gift. Consequently, I am reprinting a couple of articles that first appeared on Teleread‘s website and were written by a Teleread staffer. The articles are reprinted with permission from Teleread and are copyright 2010 by North American Publishing Company, the parent of Teleread. To reprint the articles, please contact Teleread.

The second part of the “primer” will appear tomorrow.


TeleRead E-Book Primer Part One: What is an e-book?

By Chris Meadows

kindle_new_old[1] Welcome to the first installment of my e-book guide for beginners. The purpose of this guide is to give someone who knows absolutely nothing about e-books the tools he needs to make an informed decision about what kind of e-book device, if any, to buy.

This guide is going to assume you are at least able to use a computer well enough for day-to-day uses such as browsing the World Wide Web or writing in a word processor. The guide will also be prone to revision, at least until I’m sure I have it right—so if anything confuses you, let me know

This first section of the guide will start by explaining what e-books are, and will then cover their advantages and disadvantages over printed books so you have a better idea of why you might or might not want to buy them.

Let’s begin.

What is an e-book?

In the simplest sense, an e-book (short for “electronic book”) is a computer file that contains words (and sometimes pictures) that can be read on a computer or other electronic device. If you’ve ever written a letter or a report on a word processor, then congratulations: you’ve created a very short e-book, at least by that definition.

However, when most people talk about e-books, they’re talking about a specific kind of computer file, one that is specially designed to be opened by a specific computer or other electronic device. You’ve probably heard of some of them, or seen the advertisements on TV. The Kindle, web bookseller’s device, is arguably the most popular e-book reading device (“e-reader” for short), but people talk a lot about reading on Apple’s iPad tablet device, too. And of course there are plenty of others.

But you don’t necessarily need a hand-held device to read e-books: many of them can be read right on your desktop or laptop computer, as well. Some people don’t find reading on a computer screen to be very comfortable, but on the other hand you’re probably reading this from a computer screen right now. The only difference between this and an e-book is that an e-book is a lot longer.

Effectively, an e-book is a computer file containing the same words you would otherwise find in a printed, paper book, meant to be read by a specific e-book reading device or an e-book application (program) on a computer or tablet.

However, this simple definition becomes more complicated because there are many different companies selling e-books, and most of the bigger ones want to be the only ones you buy e-books from. They try to do this by locking you in, making sure that the e-books you buy from them can’t be read on anybody else’s device or application. I will go into more detail about how they do this in the section on formats.

For now, bear in mind that there are many different kinds of e-books, but most of them are similar enough to each other that I can talk about “e-books” in general and most of what I say will be true for all of them.

Why (or Why Not) E-Books?

Since many people who talk about e-books don’t stop and explain what they’re talking about, you may not have gotten a clear idea of what e-books can do for you, and why you might or might not want them.  In order to give you a better idea, here are some of the main advantages and disadvantages of e-books. (This list is not by any means complete; I have little doubt other people will be able to think of ones I miss.)


  • Device Portability – Most modern e-book devices can hold literally hundreds or even thousands of e-books in their on-board memory—more e-books than you could read in a year, and certainly more than enough to keep you from getting bored on a long airplane ride or even a two-week vacation. And many of these devices are small enough to slip into a pants or jacket pocket so you can have them with you wherever you go.
  • File Portability – Most current e-book sellers will let you read your books on more than one device at the same time. For example, if you buy a Kindle e-book, you can read it on a Kindle e-reader device, or on Kindle Reader apps for your computer, iPhone, iPad, Blackberry, Android phone, or a number of other devices—and you can have the same e-book file open on more than one of these at the same time. (The Kindle will even keep track of where you left off on one device if you should then start reading the same book on another, though not all will do this.)
  • Instant Gratification – Have you ever heard about a book and wanted to read it right away, without having to leave your house to go to the bookstore or library? Do you live out in the country where it’s inconvenient to get to a bookstore? Or have you wanted a book in the middle of the night when the libraries and bookstores would all be closed?
  • A nice thing about E-books is that you can buy and download them immediately from the comfort of your own home, at any time of the day or night. If you’re using a reader (such as the Kindle) that has an always-on Internet connection and built-in store, you can buy them at any place, too. One of Amazon’s slogans about the Kindle is that you can be reading any Amazon e-book within a minute of wanting it, though it’s just as true for a number of other e-book stores as well.
  • Book Price – When a hardcover paper book and an e-book of it come out at the same time, the e-book version is usually priced lower. If you want an e-book of a paper book currently in $26 hardcover, you may be able to find it priced as low as $9.99. Furthermore, many e-books (such as the electronic versions of books that are now in the public domain) are available (legally) for free.
  • Easy Reformatting – Just as you can make the text size bigger or smaller in a word processor document you’re writing, you can make it bigger or smaller in an e-book you’re reading as well. A considerable number of Kindle users are middle-aged or older people who like being able to turn any e-book into a “large print edition” that they can read more easily.
  • Search Capability – If you want to find out where, or how many times, someone used a specific word in a book, or are wondering where a certain character first appeared, or want to find out any other fact, an e-book reader will let you find it much more quickly than riffling through the pages of a print book.
  • Bookmarking/Annotation – You never need to worry about misplacing your bookmark, and don’t ever need to damage a book by folding the corner of its page to keep your place. Most e-book readers will let you bookmark pages just like you might bookmark a website in your web browser, and some will also let you add short text notes to yourself tagged to particular sections.
  • Space-Saving – E-books take up no space on your shelf or in your house. They don’t contribute to clutter, and you can’t accidentally knock them off the shelf and trip over or step on them either.
  • Backup Capability – Many e-book stores will keep a record of all the e-books you buy and let you download them again in the future, so if your e-reader is lost in a housefire you can still get all your e-books back. Not all e-book stores will let you do this, of course—Apple’s iBookstore is one major holdout—but even if you can’t re-download the e-books from the store, you can usually copy them to a CD or DVD-ROM or a backup hard drive you can keep somewhere safe just as easily as you can back up any other computer file. Compare this to a shelf full of print books, which you’ve lost forever if your house burns down.


  • Requires Special Equipment – While you just need a paper book and available light to read a book, to read an e-book you need the book, the light (depending on whether the e-book reader has a backlit screen), and a device on which to read it. While e-ink readers are very efficient at conserving battery power, they do still need to recharge sooner or later; paper books never require batteries.
  • Eye Strain – This is largely subjective: some people find they have problems reading from a small screen, or a backlit screen. Others find it suits them just fine. If you’ve never tried reading an e-book, you should try several of them out in a store, or borrowed from a friend, and see what you think before buying one.
  • Format Lock-In – If you buy an e-book from one of the big e-book companies, it will come in a format that you can only read in that e-book company’s devices and applications. If you buy a Kindle e-book, you can read it on a Kindle device, or Kindle Reader applications for your computer or tablet, but you can’t read it on a Barnes & Noble Nook. I’ll explain this in more detail in the section on formats—it’s one of the biggest problems e-books have, and one of the greatest sources of confusion to new e-book users.
  • Device Expense – E-reader prices have been steadily declining over the last few years, but they still cost a pretty penny. The least expensive Kindle is about $139, though it will probably fall to $99 or below sooner or later. That’s still a lot to spend on a device you might accidentally leave on the bus or drop in the tub.
  • Book Expense – How much an e-book should cost compared to a hardcover or paperback has been a subject of considerable debate over the last few years. Amazon shocked the publishing world by pricing the e-book versions of many first-printing hardcovers at a flat $9.99, less than half what the hardcovers cost and below what Amazon itself was paying “wholesale” for each e-book it sold. Earlier this year, publishers forced Amazon to raise prices on many of these books (though a lot of them seem to have been allowed to fall back to $9.99 since). Of course, for many people even $9.99 is too much to pay for an e-book, especially since…
  • E-Books Can’t Be Resold – With traditional books, the used book store provided a way to recoup some of your investment in books you no longer need. You can buy them, read them, then pass them on when you’re done with them. You can’t resell e-books, however, because there’s no physical artifact associated with them: if you pass them on to someone else, it still leaves a copy of them with you.
  • Region Restrictions – One of the fundamental differences between printed books and e-books is that their sales are treated differently. While you can order a printed book from overseas because the point of sale is legally considered to be the country of origin (you bought it there, they’re just shipping it to you), when you buy an e-book the point of sale is considered to be your own computer. Effectively this means an American who could order a British paper book from can’t buy a British e-book of the exact same title.
  • E-Book Formats May Change – While e-book files can easily be backed up, there is no way to be completely sure that the e-book store you buy heavily into today will necessarily be around tomorrow. If a given e-book store should go bankrupt, or be bought out by someone who closes it down, people who bought that store’s e-books could find themselves in the same position as a heavy adopter of Betamax after VHS won the videotape format wars back in the early 1980s: his device and the media for that device still work just fine, but there won’t be any more media coming out for that device and after the device breaks he can’t get another. (I’ll talk more about this when I cover formats in the next section.) While this isn’t likely to happen to any of the major players at this point, it’s always possible.
  • Doesn’t Smell Like a Book – Some book-lovers simply prefer the look, feel, weight, and yes, smell—of a paper book, to the point where the lack of these aesthetic factors is one of their main objections to the format. E-book lovers often accuse them of losing sight of the fact that the main purpose of a book is not to look, feel, and smell a particular way, but to have words in it that you read. 


In this section, I’ve explained that e-books are computer files containing the words that would otherwise be printed on paper to make up a printed book, and have gone over some of their major advantages and disadvantages. The advantages include such things as the ability to carry hundreds of books in your pocket, or to buy books at any time and place. Disadvantages include the requirement of an expensive hardware device to read them and the inability to resell them.

In the next section, I will list some of the major e-book reading devices and applications, and talk about the different e-book formats that are available.


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