It has never been so easy to publish your own book. And now eBooks are becoming more and more popular. There are multiple options for reading, or publishing, including (but not limited to) Amazon/Kindle, Barnes & Noble/Nook, Apple/iPad/iPod/iPhone, and various less well known mediums.
I know from my own personal experiences of purchasing eBooks that not all books are formatted well. Now, it varies from person to person, but those formatting errors can be minor annoyances or make a book completely unreadable.
It can be something minor. I've had a couple eBooks from big publishers that didn't have a working navigational table of contents. This meant that I couldn't 'flip' between chapters, and there were no chapters listed in the 'Go To' option.
Or it can be something major. I've seen eBooks that have spaces that take up have a screen, paragraphs that break in the middle of a sentence, or a complete lack of spacing so it's difficult to tell where one paragraph ends and the next one starts.
Of course, no one wants to have problems with their book. You've spent so much time and effort writing your book. You want other people to enjoy it. So, what do you do now? How do you ensure that your book looks nice, and works with whichever device you've decided to publish on? Maybe you've decided to format/convert the file yourself, or maybe you've decided to hire someone else to do it.
Now that brings up the question: What's the difference between formatting and converting an eBook?
In short, formatting requires much more time & work and ensures a good looking/functional final product, while converting is a quick automatic process (usually involving a conversion program) and the results can be unpredictable and may look slightly off or just wrong.
Formatting a document has to do with changing the way it looks and/or functions. Formatting eBooks requires knowledge of html and css. What does that mean? HTML is the basic structure of the eBook (paragraphs, chapter headings, images, etc) while css is the style of the book (fonts, sizes, spacing, colors, etc).
Basic formatting would include things like: first line indents, paragraph spacing, font sizes, text/image alignment, ensuring the eReader device "sees" the chapters, adding and linking a Table of Contents (if it's not already there), etc...
Converting a document is simply changing it from one file type to another. For example, you have a Word Doc and you use a program to convert it to mobi.
There are many free programs available that will convert your book between many different file types. They will not ensure that the book looks good, only that it has changed from one file type to another.
Now, I'm not saying that those conversion programs are bad. They can be very useful. Calibre, for example, is a very useful, free, conversion program. You can get fairly decent results, but only if you understand what all the options mean and how they apply to your book. In fact, if your Word doc is well formatted, and if the book is simple (mostly text), you can sometime use a converter program and get decent results.
Ah, but I just said 'well formatted', didn't I? Which leads me to...
In my opinion, it's not so easy to separate the two. At least, now when everything's properly done. A good eBook will look nice (formatting) and be in the file type you need (conversion). If you skip either of these processes your book won't work out very well. If you simply convert the book, your formatting will probably not be what you want. Just like a well formatted document won't mean much if it's not converted to the proper file type.
In the end, to get the eBook you want, you'll have to both format and convert your document. If you decide to do this yourself then take the time and effort and you'll be happier with the results. Or if you decide to hire someone to do this, make sure the person you hire will take the time to properly format your document before they convert it.