When you use services from Booknook.biz, there are three file formats, generally, that you may receive back from us. Those are:

1.PDF:  this is used for PRINT LAYOUT.  If you are publishing a paperback with KDP Print, IngramSpark, Lulu, etc., this is the file that you will take to your POD (Print on Demand) company.   You'll upload the PDF that we've made for you, as the book's interior.

2.MOBI:  This is the organic, preferred eBook format for Amazon.  We'll be giving you a file called something like "my_book's_title.MOBI" and that's the file that you'll take to Amazon, and upload for your Kindle eBook.

3.ePUB:  this is the eBook format for all other eBook retailers—Barnes & Noble, iBooks, Google Books, KoboBooks (in Canada) and distributors like IngramSpark, Smashwords, etc.

4.Other files:

a.KPF:  For Print Replica at Amazon, we may sometimes provide you with a ".kpf" file.  This is a special type of MOBI file, made for art books and kids' books, typically.  This file type cannot be used anyplace else, and can only be seen or reviewed in Kindle Previewer, pre-publishing (which means you cannot sideload it to your Kindle device).

b.AZK:  this is a special type of preview file, which allows you to see how your MOBI file will appear on an iOS device, like an iPad or iPhone.  This file exists solely for a publisher to preview the appearance, and is not used for any other purpose.  

c.JPG:  JPG or JPEG is the eBook cover format that you'll need, when you go to Amazon to upload your eBook.  If you don't upload your cover image, even though we've embedded the cover in your eBook, the cover image won't display on the Amazon sales page.  You may ignore Amazon's instructions NOT to upload a cover inside the eBook, when we give you a ready-made MOBI file—those instructions are for people uploading Word files.

d.PDF Cover:  when you print a paperback, whether it's at Amazon, Ingram, etc., you must have a "wraparound cover" already made, and in PDF format. You cannot upload a full cover in JPG, TIFF, PNG, etc. It must be a PDF, made to Amazon's specifications.