Just what is an e-book anyway? Part one

An e-book reader

source: wikipedia

Ever wonder what an e-book really is? What’s inside that EPUB, MOBI or AZW file? Why should you even care? Well, understanding the core functionality and programming of an e-book can help you make better decisions to develop an e-book product that meets (and hopefully exceeds) your readers’ expectations.

The Mechanical Encyclopedia

La Enciclopedia Mecánica. source: farodevigo.es

The idea of an electronic book is not new. In fact, the first electronic book, called la Enciclopedia Mecánica, was patented in 1949 by Ángela Ruiz Robles, an inventor and teacher from Spain.

Sixty odd years and many technology advances later we have a thriving and ever-changing e-book industry, thanks to pioneers like Ángela.

Why are readers flocking to this technology? Let’s review some of the benefits:

  • You can carry many books with you. A newer Kindle Fire can store as many as 6,000 good-sized novels, assuming 1,000 books per GB of available storage.
  • E-book files are typically less expensive than printed books because there are less costs to produce an e-book than a printed book.
  • E-books are typically lighter than printed books. Even my ancient AluraTek Libre e-reader is lighter than a typical trade paperback.
  • You can immediately start reading your purchased and downloaded e-book. You don’t have to wait for shipping or fit in a trip to the bookstore.
  • E-books are marketed as more environmentally friendly than printed books (although there is debate whether this is actually true.)

E-books’ cool features rely on the reflowable e-book file format (like EPUB, MOBI and AZW to name a few).

What do I mean by reflowable? Well, think of an e-book as a kind of web site, where each chapter is a separate web page. Most of those web pages have content that is longer than one screen.

Instead of making you scroll down (like your facebook news-feed does), the e-book file finds how many characters (including spaces) can fit on one line and how many lines can fit on a single screen, and automatically figures out the page breaks for the whole book. You’ll see websites do a similar kind of pagination (like amazon or eBay listing pages).

In other words, reflowable e-books are “responsive” to the screen size of the device, and automatically reflow the text to fit the width and height of that screen.

The e-book industry would not exist without this reflowable function. Imagine if you had to create a different file for every different screen size? That would be expensive for producers and confusing for consumers.

The early developers of mobile websites ran into similar issues, and since the adoption of HTML5 and CSS3, have developed “responsive” web design. In responsive design, the web site is designed to recognize the width of the screen on which it is being displayed, and adjust the design (sometimes radically) to fit that screen and still be legible and functional. Here’s an example:

responsive web design example

An example of responsive web design, showing both a desktop computer and smart phone view of the home page. Source: mobify.com and thepaintdrop.com

Other cool features of e-book files that allow readers to customize the experience:

  • All devices allow the reader to change the size of the font or typeface in some way.
  • Some devices allow the reader to change fonts or typefaces in the e-book altogether.
  • Most devices allow the reader to change from portrait to landscape view.
  • Most devices allow the reader to change the color or shade of both the text and background.
  • All devices use the navigational table of contents built into e-book file formats, allowing the reader to jump to a certain section automatically.

When you add in benefits of specific devices (like wifi-enabled e-readers) you can see why readers are adopting e-reading en masse.

In the next installment, we’ll look “under the hood” of a typical e-book file and have a closer look at its parts.



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