What is an ebook
An eBook can be a digital version of an existing book or it was written as an entirely new eBook. An eBook is never printed but is exclusively shown in digital format on a screen. That can be a monitor but it can also be a special purpose-built device. These devices are also known as e-readers. Mobile phones and tablets are also suitable for legibly displaying eBooks.
A growing number of people own an e-reader or tablet, so they also buy increasingly more often eBooks. Publishers as well as authors increasingly more often deploy eBooks in order to meet the growing demand for eBooks.
eBooks can be delivered in a (growing) number of different formats. The ultimate choice depends on the technical feasibility and your preference. In principle, there are four types of eBook formats. PDF is still the most common. This can be easily read on a monitor but is less suitable for e-readers. Besides PDF, the Kindle (AZW), MOBI, IBA and ePub formats were introduced. These formats are excellent choices for smaller types of e-readers, phones and tablets. As opposed to the other formats, the ePub format was embraced by almost all major publishing companies and is therefore support by virtually all e-readers/PCs. Kindle can only handle the mobipocket format, which is a derivative of the ePub format. IBA is an explicit Apple file. Apple is the only one to also support a so called fixed layout format, based on the screen of the iPad and iPhone. Because this is (for the time being) an Apple specific file, it is not recommended to layout files in this format. ePub has standard because it is widely supported.
What is PDF
PDF (Portable Document Format) is a standard for exchanging electronic forms and documents that need to be reproduced in their original form. PDF is a universal layout, which preserves the fonts, images and layout of any document, regardless of the program or the platform that was used to create the document. An advantage of files in PDF format is that these, as opposed to for example files in Word format, look exactly the same on any printer. Furthermore, PDF files can be viewed and/or edited on any operating system. For opening a PDF file you need a PDF reader program such as for example Adobe Reader.
What is ePub
ePUB (an abbreviation of Electronic Publication) is a free and open eBook format, which was developed by the International Digital Publishing Forum (IDPF). ePub is the file extension of a type (XML) that can be used for eBooks for example. An .epub file is a combination of three open standards, the Open Publication Structure (OPS), the Open Packaging Format (OPF) and the Open Container Format (OCF). The advantage of an ePub is that the text adapts itself to a screen (reflowable content). On a small screen, the sentences are automatically made shorter or the text smaller, on a large screen longer and larger. In PDF format, that is not the case and therefore, it is harder to read PDFs on small screens. The layout of an ePub eBook is similar to HTML code, which is also used to lay out websites.
What is AZW (Kindle)
Amazon, the largest US online retailer, does not offer books in the .ePub format. Amazon has developed its own type of file, based on the .mobi file format. The only difference lies in how Amazon adds a DRM (Digital Rights Management, protection of eBooks). The file extension is .AZW. Fortunately, we are able to convert an ePub file to .mobi and next to azw relatively easy and simply. The azw format is an example of a so called "closed" format, just like Apple’s IBA. It is the property of Amazon and therefore, it can only be read using Amazon devices such as the Kindle. It is impossible to export to ePub.
What is MOBI
MobiPocket was one of the first file formats to be introduced to the market. It was developed by French company MobiPocket SA, which was founded in 2000. In 2005, MobiPocket.com was purchased by Amazon.
What is IBA
IBA is a closed file format that was created by Apple. Using special software, it is possible to create an eBook that includes various functions that are not (yet) possible in ePub or Mobi. The design is geared to iPad and/or iPhone screens. The main disadvantage is that these eBooks have to be sold exclusively via Apple and are impossible to read on other devices. It is impossible to export from IBA to ePub.