ebooks FAQ
Frequently asked questions about ebooks and ereaders

An ebook is any electronic or digital version of a book, pamphlet or any type of document.  They are files which can be read on personal computers, PDAs, phones, or dedicated reading devices which are commonly called ereaders.

There are several different kinds of ereaders which all have their strengths and weaknesses which you should weigh before deciding which one to purchase.  Most ereaders are now equipped with "E Ink" screens, which display text and images without the use of back lighting making the text easier to read for long periods of time and visible even when read in full sunlight.  The difference between the devices range from screen refresh rates, screen size, the type of file formats they accept, storage size, battery life, etc.

There are also an ever-increasing number of ebook file formats, and most ereaders can view several different types.  It’s important to understand what types your device is compatible with. Also keep in mind that each format can sometimes be referred to by multiple names or file types.  

It is also worth noting that sometimes you can convert ebooks from one format to another, but this depends on what kind of Digital Rights Management (DRM) limitations the file has.

Listed below are some examples of dedicated reading devices.  There are hundreds of other devices that can be used to read books, from iPhones, Palm devices, Blackberreies, to personal computers, etc but the following are dedicated reading devices which all use E Ink technology.  Some of these devices also double as personal audio devises or have other features so read up before making your purchase decision.


Name Released Screen Size Mac/PC File Types Notes (Languages supported)
Nook Nov 2009 6" (+ 3.5" LCD) PC/Mac pdf, eReader, ePub, pdb, Mp3, free wi-fi in B&N stores, digital lending, US only (Eng.)
Cool-er June 2009 6" PC pdf, html, txt, rtf Mp3, Audible (Eng, Chinese, Jp, Es, Fr)
FLEPia April 2009 8" or 12" PC Microsoft Office Files, WinCE apps Full color, touch screen, 1.8-8 sec refresh rate, Japan only (Jp)
Kindle 2/DX 2009 6" / 9.7" Mac/PC azw, txt, mobi, prc, pdf, html, doc, pdf, txt Text to speech, Mp3, Audible, nearly worldwide wireless (Eng)
eSlick 2009 6" PC pdf, txt Mp3 (Eng)
SonyPRS-700BC 2008 6" PC pdf, txt, rtf, doc, BBeB, ePub Mp3, Audible (Eng) (Same stats for 505BC)
Digital Reader 2008 10.2" PC pdf, html, txt, mobi Touch Screen (Eng. Nl, De, Es, Sp, It)
Cybook Gen3 2007 6" PC pdf, mobi, prc, PalmDOC, html, txt Mp3 (Eng, Fr, De, Es, Sp, It, Nl, Pl, Ru, Sl)
HanlinV3 2007 6" PC pdf, txt, rtf, ePub, lit, ppt, wolf, doc, chm, fb2, mobi, html, djvu Mp3 (Eng, Chinese, Ru, Uk, Tr, Fr, Es, De, Nl, Kor, Bul, Pl, Est)
 ILiad  2007  8.1"  PC  pdf, html, txt, mobi  (Eng)


As you can see there are a dizzying array of different ebook formats, which can make your first foray into the ebook world can be confusing.  Many of the different ereader manufacturers have their own ebook format that is unique to that reader, and there are also general formats that most readers can view (i.e. txt, pdf, et al).  The following list should give you a good start on understanding what the different formats are and which will work with your reading device/program.

ebook formats

Proprietary ereader file formats:

AZW - Amazon’s file type for the Kindle series of ereaders.  The AZW extension is used on ebook files that are protected with DRM and files that are not protected.
PRC/MOBI – is the file extension of the Mobipocket reading software.  In either case it may be DRM protected or non-DRM
LIT - a filename extension for Microsoft Reader ebooks
 PNPd/PDB – the format for the Palm ereader
 LRF/LRX/LRS/BBeB – BBeB is Sony’s format.  It is also called LFR for its file extension: LFR denotes DRM free files and LRX file types are encrypted and can be set to expire.
STK  - the extension identifying STARebook's proprietary format

Secondary ebook file formats:

PDF – Adobe’s “Portable Document Format” is immensely popular but often does not format well to the small screens of ereaders.  However despite its drawbacks it remains a popular format.
TXT – Plain text format, readable by most ebook devices
RTF – Text format for Word and Office, readable by some ebook devices
DOC – this can refer to Microsoft Word format, or PalmDOC format which is used by PalmOS devices.
HTML – Hyper text mark-up language, aka the language most web pages on the Internet are coded in
CHM – Compressed HTML files, also used for Microsoft help files
FB2files FB2 file extension is a HaailReader ebook file supported by FBReader AIReader, Haali Reader and okular under Lunix.
– File format for the HanLin device
DJVU - DjVu has been promoted as an alternative to PDF, as it gives smaller files than PDF for most scanned documents. In 2002, the DjVu file format was chosen by the Internet Archive as the format in which its Million Book Project provides scanned public domain books online (along with TIFF and PDF).
EPUB - EPub is a free, open standard for "reflowable" content, meaning that the text display can be optimized for the particular display device.
ACSM - File format used to provide DRM on Adobe ebooks PDF and ePUB
FUB - FUB stands for Franklin Universal Binary. It is the ebook format for the Franklin eBookMan reader
KML- is the extension used for Hiebook ebook files
PPT – Power Point files
-is.PDB  - A palm database format for the ISilo reader.  The "is" is used to distinguish this format.

Once you have worked out what ereader you want to use, and what formats your ereader can support you can start searching out ebooks to read.  There are dozens of places to download ebooks online.  Keep in mind that some of the sites (ie: Amazon or Sony) which only sell their own ebook format, also some sites (ie Project Gutenberg) allow you to download public domain (expired copyright) ebooks for free.  The last thing to pay attention to is that some ebooks contain DRM systems which limit your ability to transfer copies of the files to multiple devices, this doesn’t affect the readability of the book but in some cases can prevent you from transferring the ebook to another reading device.  So be sure to check these details before purchase to ensure your ebook has all the features required.

Where to buy your ebooks

ebook stores Publishers Free public domain ebooks
Sony ebook store Simon and Schuster Project Gutenberg
Amazon ebook store Penguin Free ebooks
ebooks.com Tyndale House Publishers Many Books
Kindle Shops ebooks Noble Romance Publishing  
Fictionwise Harlequin  
WH Smith Baen  

Foreign language ebook stores

Liberka.de - German
Libri.de  - German
Todo ebook - Spanish
Leer-e - Spanish
NumiLog - French
ebooks Gratuits - French

New reader's, format's and website's for ebooks are being created at a very rapid pace, we do our best to keep this page up to date but if you are ever stuck a good resource for ebook information is the website http://www.mobileread.com/.  It contains a blog, wiki and forum for ebook users and should be able to help answer more specific questions about different readers and formats or help with trouble shooting questions you might have.