What is the difference between a print book and an ebook with reflowable text?

Here is an explanation of Ebook Launch’s terminology with regard to books, print books, and ebooks (If you would like Ebook Launch to format your book, please submit it for a quote here: https://ebooklaunch.com/formatting-quote-form/):

Whenever Ebook Launch uses the term “ book” in the general sense, we may be referring to either a print book or an ebook. When we refer to a “print book”, we are specifically talking about a physical book, printed on paper. When we refer to an “ebook”, we are talking about the digital or electronic version of a book, which is viewed on an electronic device.

Most print books and ebooks use similar conventions, such as a cover page, title page, copyright page, table of contents, chapters, and paragraphs. However, there are some notable differences between print books and ebooks - especially when considering ebook formatting and print book formatting:

Layout: Print books have a fixed layout that you can control, and does not change after printing. Ebooks have a reflowable layout that appears different depending on the device, application, or user settings used to view the ebook. Reflowable formatting refers to the text's ability to "flow" or automatically wrap words in a document to the next line as the settings change. This flexibility of ebooks allows each reader to enjoy the ebook according to their own preferences, on their own device or application. Because there are not pages per se in an ebook, one cannot 'center' the text vertically.
Page numbers: Since ebook text "flows" to adjust to the size of the screen and user settings, an ebook does not have set pages or page numbers, as in a print book (any page numbers you see in an ebook are placed there by the ebook's software). Therefore, the reader cannot use page numbers as a means of navigating and referencing locations within the ebook through the table of contents or index. Instead, ebooks have a table of contents that is hyperlinked to the individual chapters and/or sections of the book. And instead of the index, users use the device or application’s search function to locate specific words or phrases within the text.
Headers and footers: As there are no set pages or page numbers in ebooks, they do not have headers or footers. Any headers and/or footers you see in an ebook are put there by the ereader app or device using the ebook's metadata.
Endnotes: Again, as there are no set pages in ebooks, footnotes found in a print book, become linked endnotes within the ebook.(if Word's footnote function has been used)
Images: To ensure predictability of placement, images are in line with the text and centered. Charts and tables are converted into images and formatted accordingly. If there are captions associated with the image, because of reflowable text, there is no guarantee the caption will be on the same screen/page as the image.
Cover: Since ebooks are two dimensional, they do not have a spine or back a back cover.

In an ebook, depending on the ereader app or device, the reader can set the following preferences:

font type
font size
page width
hyphenation
text alignment
color mode

The following are some examples of preference setting for the Kindle for Mac/PC (these also demonstrate reflowable text and the dynamic nature of ebooks):

Every ereader app or device is different, but the Preference selection for the Kindle for Mac/PC can be accessed by clicking on the "Aa" button: