What are ebooks?

Ebooks have been around for a while now and still the definition can be a bit blurry. So, what are ebooks?

According to Wikipedia, an ebook is ‘an electronic book’ or ‘digital book’. In other words, it is a book-publication in digital form, consisting of text, images, or both, readable on computers or other electronic devices.

Just like a printed book, an ebook has a cover, a blurb and content. An ebook can have all the characteristics of a print book, such as an ISBN, an author, an editor, an illustrator, a publisher, etc.

ebook — e-book — eBook

There are many versions, but it seems ‘ebook’ is winning the race.
This is also the preferred spelling in the Macquarie Dictionary, which I am following here.

What is the difference between a PDF and an ebook?

What are ebooks? Image of a page of a PDF file when opened on an smart phone
When a PDF is opened on a smart phone, only this section is visible. The other text is outside the view.

Strictly speaking, a PDF is an ebook. The PDF (an abbreviation for Portable Document Format, developed by Adobe) has been, until recently, the best known and most widely used ebook format.

However, books in PDF format, and many other fixed-page electronic formats, have the same disadvantage as print books: a lot of time and effort has to be spent on page layout and they are hard to read on small screen. Electronic book formats such as PDF also restrict the reader to a particular software program, and they need to be read and displayed at a readable size (i.e. a normal computer screen).

In the past, this was probably the reason why publishers rarely sold published books into those fixed-page formats.

The rise of smart phones and tablets has gone hand in hand with the development of new ebook formats (e.g. EPUB, MOBI) that no longer have these disadvantages. Because of this, ebook publishing has changed a lot. We can now read ebooks on many devices and no longer have to sit behind our computers.

The main difference between formats such as PDF and the new ebook formats such as EPUB is that the new formats ‘reflow’ the content.

What is reflowable content?

File formats such as PDF have a ‘fixed’ page layout. This means that the content on the pages is always the same and does not change when you open the PDF on a different device.

The new ebooks, however, are produced in a format that no longer fixes the page content. Instead, the page content changes when you open the ebook on a different device (or on the computer when you change the size of the program window). This is possible because the new file formats allow the book content to ‘reflow’, i.e. the content adapts to the device on which it is read (like water takes on the form of its container).

The following examples show what happens when ebook content is reflowable.

What are ebooks? Image of a double page spread of A Voyage to New South Wales in Adobe Digital Editions
A double-page spread of the ebook ‘A Voyage to new South Wales’ in Adobe Digital Editions on a computer screen.
The fraction of the page content you would see if this was a PDF opened on a smart phone
The fraction of the page content you would see if this was a PDF opened on a smart phone.

The example I am using is from the book by John White, ‘A voyage to New South Wales’, in EPUB format (a most interesting journal by the first-fleet doctor about the plants and animals they found in Australia in 1787).

In the first image, taken on a computer screen, the ebook content is spread over a double page using Adobe Digital Content (see below, How to read an ebook on your computer?).

If the same document was in PDF format and opened on a small screen, you would only see a small section of the page (see second image). To read all the content on the page, a reader would have to use the scroll buttons to move the document from left to right and up and down. This would become very irritating.

This is the main reason non-reflowable text formats are used less and less for ebooks.

When content is in a reflowable format, as shown in the screen shots below taken on an iPhone 5, the text wraps and adjusts to the much smaller iPhone screen. The reader does not have to use scroll buttons and can continue reading. Below, I show the first two pages of the same document content displayed on the iPhone.

What are ebooks? Image of the text on an iphone screen
The same text reflowing to the page size of an iPhone. These are the first two pages.

In the same way, the content will take the size of any display screen so users no longer have to zoom in.

The two main reflowable ebook formats used for ebooks are EPUB and MOBI. The EPUB file format is a free and open standard format and is used by books that are for sale at most ebook bookshops. The MOBI file format is used by Amazon Kindle for all their ebooks.

How does reflowable content work with images?

This reflow capacity of ebooks also applies to text with images or illustrations. For example, the screen capture below, taken on my computer, shows a double page spread of the same ebook on Mozilla Firefox epub reader (which also has a clickable contents table on the left).

What are ebooks? Image of the ebook text in Mozilla Firefox
A Voyage to New South Wales shown in Mozilla Firefox EPUB Reader.

The same content on the iPhone 5 below spreads over several pages (I show the first and last page). You can see that the image is adjusted to fit on the small screen.

What are ebooks? First page of the same text on an iPhone 5
First page of the same text on an iPhone 5.
What are ebooks? Last page of the same text on an iPhone 5
Last page of the same text on an iPhone 5.


This great flexibility of EPUB and MOBI formats explains why ebooks have become so popular.

Reflowable content lets the reader take control

Even though ebooks have a list of advantages for publishers, readers are the ones who benefit most. They no longer have to scroll to see content and also get a whole range of controls they never had before.

Thanks to reflowable content, readers can be given control over the font size, colour and even the indentation of paragraphs as they read. This is great for accessibility. People with good eyesight can read the text in small font, while readers who have problems with small font can enlarge the font size to the size they need with the click of a button — I love reading without my glasses! In addition, reflowable ebooks are also easier to convert into audio, which makes them even more accessible.

On many readers you can also change the colour of the page background, the light intensity of the screen, control blue or red light, set the font type, etc. Below, I show some of the different views I can get on my smart phone, without having to change anything to the publication file itself…

What are ebooks? Image of ebook text displayed on an iPhone 5
Large, sans-serif, white font on a black page background.
What are ebooks? Image of ebook text displayed on an iPhone 5
Small, serif, black font on a white page background.
What are ebooks? Image of ebook text displayed on an iPhone 5
Medium, sans-serif, black font and a sepia page background.


The advantages of ebooks

The advantages of ebooks are there for readers, writers, publishers and the environment. Here is a summary.

For readers

When reading an ebook you can:

  • read the same reflowable ebook on the computer, tablet or smart phone without the need for enlarging or scrolling — the content adjusts to the screen size
  • choose the size of the font, the font type and the colour of the font and background page
  • add as many bookmarks or highlights to your ebook as you want
  • automatically find the place where you stopped reading the previous time
  • have your library in your pocket or keep it online to access from anywhere in the world — travelling with ebooks is easy
  • purchase ebooks at lower cost (because writers and publishers can produce ebooks cheaper)
  • have access to millions of books online, many for free because copyrights have expired
  • purchase ebooks online from anywhere in the world and receive them moments later
  • have a good feeling that ebooks are better for the environment than print books.

Accessibility for vision-impaired readers is also a great benefit. Font size adjustments, brightness of screen and conversions to audio books are all new options that were very expensive for print books.

For writers

In addition to taking credit for the benefits to readers, as a writer you gain by being in a better position to self-publish an ebook. You can choose to self-publish your book as an ebook because the production process is shorter than for print and does not require the same financial investment. If you are IT literate, you can learn how to produce and publish your own book. You will have no expenses for page layout, conversion into other formats, printing and transport. The internet makes it easier to market and sell your books to the whole world from your own website, and also gives you the option of interacting with your readers.

For publishers

Ebooks may be reorganising the publishing world, but books will not disappear — there will always be writers who write books and readers who want to read them. Therefore there will always be publishers.

Publishers benefit from the ebook transformation because the whole production process has become cheaper, easier and sales are now possible worldwide. Publishers have the same advantages as writers, but they are still the expert on quality writing and publication delivery. For those writers that prefer to write, a publisher is still the best way to publish a high-quality book.

For the environment

Print production is not only expensive for readers, writers and publishers. It is also expensive for the environment. Ebook production removes a suite of production steps that damage the environment.

To produce an ebook:

  • you do not need to chop trees to make paper
  • there is no paper processing or bleaching, no ink production, no printing, and less waste, so less chemicals end up in the environment
  • there are less greenhouse gases for transport (transport is instantly over the internet).

How to read an ebook on your computer?

Where to start with your first ebook? I suggest the first step is to read a free ebook on your computer. This way, you do not have to purchase anything or subscribe to any online ebook service.

Before opening an ebook on your computer, you need to make sure you have the software on your computer to read it. For some reason, standard computer installations do not yet come with ebook readers. (I have just installed Windows 10 on a new laptop, and when I try to open an EPUB ebook, it takes me straight to the Microsoft store login…) It is obvious that the various large companies involved (i.e. Apple, Amazon, Google, Microsoft) prefer you purchase their apps, ebooks, ebook devices and software through their own systems, rather than show you how to set up your own library by downloading ebooks from the web. Luckily, there are many ways around this and it is not very hard to find free ebooks and software online.

Here are a few software programs that will read EPUB format ebooks.

Mozilla Firefox EPUB Reader

This program is the most simple and is my recommended choice.

  • download and install the Mozilla Firefox internet browser for Windows and Mac — a free and open-source internet browser
  • browse to EPUBReader (a Firefox add-on) and install it — the instructions on this website explain how to install it
  • see the section below on how to obtain your own free ebook
  • click on the ebook file link in the email to open the ebook in EPUBReader
  • start reading!

Adobe Digital Editions

This software is by Adobe and is free. It is simple to use, but you will need to download the epub file to your computer and open it in the program before you can start reading.

  • download and install Adobe Digital Editions (for Windows and Mac)
  • see the section below on how to obtain you own free ebook
  • download and save the ebook to your computer
  • open Adobe Digital Editions
  • select File>Add to library to find the downloaded ebook on your computer
  • select the ebook file to open it in Adobe Digital Editions
  • start reading!


This software is also free, but they do appreciate donations. However, Calibre is much more complex than the previous two programs. In addition to reading EPUB ebooks, it can read many other formats, convert formats, build an ebook library, and even create new EPUB publications. I would only recommend this program for more experienced users, but it is excellent value.

The most useful feature for beginners is that you will be able to search for ebooks on the internet from the program itself and add them to your library.

  • download and install Calibre (for Windows and Mac)
  • see the section below on how to obtain you own free ebook
  • download the ebook to your computer
  • open Calibre and click on Add Books to find the downloaded ebook on your computer
  • select the ebook file to open it in Calibre
  • start reading!

Download the free EPUB ebook

What are ebooks? A voyage to New South Wales
FREE ebook ‘A Voyage to new South Wales’ by John White

The ebook ‘A Voyage to new South Wales’ is available for free for readers of this post. There are many other free ebooks available online (see below).

To download the ebook:

  • click on the following link ‘A Voyage to New South Wales
  • click on the Free Download button and then on Checkout to go to the check out.

You will be asked to submit your email address so that you can receive the link to the ebook. You will not have to pay.

When you receive your ebook email:

  • click on the link to the book in the email
  • if you have installed Mozilla Firefox and the EPUBReader, the ebook will automatically open in Firefox and be added to your EPUBReader library
  • if you have not yet installed EPUB reader software, you can download the ebook file to your computer and follow the instructions above on how to install an ebook reader.

More information on ebooks

In this post, I have concentrated on mainstream ebooks and those formats with reflowable content. The following sites are excellent resources on various other aspects of ebooks.

  • Comparison of ebook formats: Have a look at this Wikipedia site if you are interested to know more about the various formats of ebooks that exist. It shows an excellent comparison table of the various features associated with each format type.
  • Comparison of ebook readers: This Wikipedia site provides a list of ebook readers that exist. It shows an excellent comparison table of the various features associated with each reader.
  • Comparison of Android e-book reader software: If you have an Android smart phone or tablet, this site lists the apps you can use to read ebooks on your device.
  • Comparison of iOS e-book reader software: If you have an iPhone or iPad, this site lists the apps you can use to read ebooks on your device.

Sites with free EPUB ebooks

There are many sites out there with free ebooks, though you have to be careful which sites you use. These are my favorites:

Project Gutenberg: This site has over 50 000 free ebooks that can be downloaded. It is a highly reliable site that does not have a commercial interests.

Project Gutenberg Australia: The Australian part of the above organisation has more Australian documents.

eBooks@Adelaide library: Connected to the University of Adelaide, Australia, this site presents many of the library’s works online. Free to read through their own browser online and also available to download to your computer.


I am happy to answer your questions about ebooks. Please use the Reply option below to ask a question.


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