When we say that text “reflows,” we mean that when a user changes the font size, or the font, the text adjusts.  If the font is bigger, there will be fewer words per line, and fewer per page.  From beginning to end, the text changes to suit what the user has asked it to do.  You can see examples in this article: Is it true that readers can change how my book looks? and in this article addressing how the appearance of a book alters just by changing the font size.  If a font is enlarged, the screen will display fewer words per line, which means that the next paragraph will have moved downward, in this case (the example images--click to lightbox and zoom) to the next page.

The Prince and the Pauper, on Adobe Digital Editions Reader, with the font size set at medium.  Note the purple-highlighted text.
The Prince and the Pauper, on Adobe Digital Editions Reader, with the font size set at medium. Note the purple-highlighted text.

 

For example, look at what happens when we do nothing but change the text size of an ePUB, shown here in Adobe ePUB reader, of Mark Twain's beloved, "The Prince and the Pauper."  In the example on the left-hand-side, the text is set at the default medium size, and we've highlighted some text on the same "page" as the image in purple.  In the first image, on the left, you see that the text occurs on the same "page" as the image.  When we resize the font, however, by using the lower-case "a's" at the top of the reading pane, merely one size larger, you'll see that the very same highlighted text "moves" to the next page (screen), and is no longer visible on the same screen (page) as the illustration. This is because it "reflows," using larger letters, fewer characters and words per line, and the entire book is re-rendered, from beginning to end. In this example, the highlighted text moves from being on the same "page" (screen) as the illustration, to the next "page" (screen), because it's reflowing to accommodate the larger font size.  

This is what we mean when we say that text “reflows" and that it is very difficult to try to control what a user sees at any given time.  EBooks are not like PDFs or print, and it will be very helpful for you to understand this early in the process so you can learn not to worry about things that cannot be controlled.

The same book, The Prince and The Pauper, in the same reader, but now the person reading it has set the font size simply one click larger.
The same book, The Prince and The Pauper, in the same reader, but now the person reading it has set the font size simply one click larger.

Our sincere thanks to Ignacio Fernández Galván for graciously agreeing to let us use his lovely ePUB creation of "The Prince and the Pauper" for demonstration and explanation purposes on our website.  Ignacio--you're a steely-eyed ePUB Pilot. 

T'was the Night Before Christmas... 

 (With apologies to Clement Clarke Moore, may he forgive my doggerel...)

...and all through the shop,
all we minions were working,
   until ready to drop.

The ebooks were flying,
the covers were spare,
The edits were crazy,
   with "one more thing I must share!"

We waited for Santa,
'Cuz we love old Saint Nick,
But Hitch made us work,
   Waving 'round an old stick!

So slave we all did,
And made all your books,
So that Hitch would say now,
   that we're off the hook.

Come today we're off,
to rest up our fingers,
Our hats we will doff,
   No books they do linger.

But we'll all be back,
Don't give it a thought,
for like all wage slaves,
   we're easily bought.

We'll be back on the fifth,
all eager and fresh,
All ready for you,
   after a well-deserved rest.

So Hitch wants to say,
very strongly and loud,
THANKS ALL YOU GUYS,
  you're the best type of crowd.

Indy and Len and Hitch and the gang,
will be back on the 5th,
to do books with a BANG!

In the meantime don't worry,
if you're in a hurry,
'cuz some poor guy got stuck
   sitting here like a duck.

Your emails we'll receive,
so no need to grieve.
We'll be a bit slow,
but we're raring to go.

Your books will be worked on,
your edits still made,
we're just resting a bit,
   before we all fade.

So please excuse the delays;
It won't be for days;
we'll jump on your queries,
   for your wondrous new series.

We waited for Santa,
'Cuz we love old St. Nick,
And sure 'nuff he came,
   It wasn't a trick.

And as he rode off,
into the night,
I could swear I heard Hitch yell,
   "That Edit's Not Right!"

~~~~~~~~~~

We'll be back on the morning of January 5th; we'll be here parttime between now and then, thanks.