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So strictly speaking, there are no galleys anymore. I always wince when I see people use that term now.
Actually, there are--but they're used by production departments. Authors are spared the galley stage, unless it's a coffee table art book.
When I'm asked to license images, or assist with a non-roman text issue, I'll see galleys. The final typesetter will still get marked up galleys.
It's so embedded in the process, that the workflow and data management programs still have the same stages:
Submission
Copy editing
Proofing
Galleys (no page numbers; figures have temp placement--some publishers will use a standard figure to come image)
Page proofs (Pages numbers present, all front matter present, all figures and captions present, index lemma terms if not entire index present)
Page proofs are what most authors get; and mostly, they'll be .pdf unless you're working with a specialist publisher doing high end art books, or a similar special case. Production staff will have printed out at least one complete copy, and will have at least a cover concept and back matter text.
I'm going to
link to the Wiley page; it's got the clearest explanation of where the forks occur (galley or page proofs) and what things mean.
I note that for my current book--where I'm functioning as an author and not production staff--we received separate proofs for the printed book, and for the various ebook versions, the .pdf sold via O'Reilly, the Kindle sold by Amazon, and then the just released epub version sold via Apple's iBooks store. For the digital versions we received what were essentiall "beta" versions, or soft proofs, in the native file format for the final book.
When you go to an ebook, whether it's co-current with paper or it's a digital only book, there are some differences in terms of setting the text as well as a number of other issues.
Production staff need to be sure captions and figures aren't separated. Chapter openings can be tricky for a number of reasons. Production staff need to be smart about whether the ebook file format will be static (.pdf) or reflowable (epub). There are other issues as well.
There are a lot of reasons why going from MSWord to digital is not the best solution--among them the reliance on MSWord handling high aschii characters like em- and en-dashes, curly quote marks and apostrophes, ellipses, and syncope.
It's especially tricky in fiction, because punctuation in dialog can be over-corrected and thus made wrong by MSWord--especially if there are em-dashes, or uses of contracted words like 'tis.