Will an eBook look exactly like a printed book?

No. To understand why not, it's important to understand the differences between print and electronic book formatting.

While the formatting possibilities in print are virtually unlimited, the final product–the physical book–is painfully inflexible. Once a traditionally-published book is formatted for print, making changes to the content or the layout of the book is a tedious, time-consuming and expensive process.

Publishing electronically is different. Instead of the inflexibility of ink on paper, electronic books keep the content and presentation of your book separate. This means that things like fonts and page size can be changed, even after your book has been formatted. As you can imagine, this allows for much greater flexibility in how your book can be read.

This means that eBooks can easily scale from small, hand-held devices like Apple's iPhone, all the way up to large-format eReaders like the iPad.

The disadvantage, of course, is that it's harder to predict exactly how a book will look on any given eReader due to slight differences in each device, like the default font they use and the physical size of their screens.