Ebook and self-publishing glossary

Plain definitions of 26 terms you meet when you write, format and sell an ebook, from AI-assisted content to workbook. Each definition stands on its own, and each has a link you can share.

Updated 12 November 2026. Amazon KDP details were checked against KDP help pages on that date.

Terms and definitions

AI-assisted content: Under Amazon KDP's guidelines, content you created yourself and then used AI tools to edit, refine, error-check or improve, or content you wrote after using AI only to brainstorm ideas. As of November 2026, KDP does not require you to disclose AI-assisted content. See: KDP rules on AI content.
AI-generated content: Under Amazon KDP's guidelines, text, images or translations created by an AI-based tool, even if you edited them substantially afterwards. As of November 2026, KDP requires you to declare AI-generated content when you publish or republish a book. See: KDP AI disclosure checker.
Back matter: The pages after the last chapter of a book, such as acknowledgements, an about the author page, a list of resources, an index or a page pointing readers to your other work.
Blurb: The short description of a book shown on its store page or back cover. A blurb says who the book is for and what they will get from it, usually in 100 to 200 words.
Copyright page: A page near the front of a book that states who owns the copyright and in which year, and often lists the edition, the publisher and the ISBN if there is one.
DOCX: The file format of Microsoft Word documents. A DOCX ebook file can be edited in any word processor, and Amazon KDP accepts DOCX as an ebook manuscript format.
Ebook: A book published as a digital file to be read on a phone, tablet, computer or e-reader. The most common ebook formats are EPUB and PDF.
EPUB: An open ebook file format in which the text reflows to fit the screen and the type size the reader chooses. EPUB is the format most ebook stores ask for, and Amazon KDP lists it among its recommended manuscript formats.
Fixed layout: An ebook in which every page keeps an exact design, like a printed page, so text and images do not move when the screen size changes. It is used for image-heavy books such as children's books and cookbooks. A PDF is always fixed layout.
Front matter: The pages before the first chapter of a book: the title page, copyright page, dedication, table of contents and any foreword or preface.
ISBN: International Standard Book Number, a unique number that identifies one edition and format of a book. Each format, such as paperback and hardcover, needs its own ISBN. On Amazon KDP an ISBN is optional for ebooks, and KDP offers a free ISBN for paperbacks and hardcovers.
KDP (Kindle Direct Publishing): Amazon's self-publishing service, which lets authors upload ebooks, paperbacks and hardcovers and sell them in Amazon stores. Ebook authors choose a 35% or 70% royalty option for each book. See: KDP royalty calculator.
KDP Select: An optional 90-day Amazon programme for Kindle ebooks. An enrolled ebook is included in Amazon's reading subscription and can use promotions such as Free Book Promotions and Kindle Countdown Deals. In return, the ebook can only be distributed through KDP and public libraries during the enrolment period, which renews automatically unless you turn renewal off.
KENP (Kindle Edition Normalized Pages): Amazon's standard measure of an ebook's length, designed to count pages the same way across devices and display settings. Authors in KDP Select are paid for KENP read by subscribers, from a monthly fund, the first time a subscriber reads each page, up to 3,000 KENP per title per customer. See: KENP earnings calculator.
Kindle Unlimited (Kindle+): Amazon's reading subscription, in which members read enrolled books without buying each one. As of November 2026 KDP's English help pages call it Kindle+; many authors and older pages call it Kindle Unlimited. Ebooks join it through KDP Select.
Lead magnet: Something useful given away free in exchange for an email address. A lead magnet ebook is usually a short guide of 2,000 to 5,000 words that solves one small problem for a potential customer. See: How to make a lead magnet ebook.
List price: The price you set for your book in a store, before any discount the store applies. On Amazon KDP, as of November 2026, the 70% royalty option requires an ebook list price from $2.99 to $12.99 on Amazon.com. See: Book pricing calculator.
Manuscript: The complete text of a book before it is published. In self-publishing, the manuscript file is what you upload to a store, typically as a Word document or an EPUB.
Metadata: The information that describes a book to stores and search engines: title, subtitle, author, description, categories, keywords, language and price. Good metadata helps the right readers find the book.
PDF: Portable Document Format, a file that shows fixed pages exactly as designed on any device. PDF is the usual format for ebooks sold or given away directly, such as lead magnets, and for files sent to print.
Print on demand: A way of publishing printed books in which each copy is printed only when a customer orders it, so the author does not pay for or store stock in advance. Amazon KDP prints paperbacks and hardcovers this way.
Reflowable layout: An ebook layout in which text is not fixed to pages but flows to fill the screen, adjusting when the reader changes device, orientation or type size. EPUB files are normally reflowable, which is why an EPUB has no fixed page count.
Royalty: The share of a book's price paid to the author for each sale. Amazon KDP pays ebook authors either 35% or 70% of the list price, with a delivery cost deducted on the 70% option. See: KDP royalty calculator.
Self-publishing: Publishing a book yourself, without a traditional publisher. The author arranges writing, editing, cover and formatting, uploads the files to a store or sells them directly, and keeps control of the rights and the price. See: Self-publishing cost calculator.
Trim size: The width and height of a printed book's pages after the printer trims them, such as 6 x 9 inches. Trim size, font and line spacing together decide how many pages a word count makes. See: Word count to pages.
Workbook: A book that combines short explanations with exercises, prompts or blank spaces for the reader to fill in. Coaches, teachers and course creators use workbooks so that readers practise what they learn.

Sources for Amazon KDP terms

Common questions

What is the difference between EPUB and PDF?

An EPUB reflows its text to fit any screen and type size, so it suits e-readers and ebook stores. A PDF has fixed pages that look the same everywhere, so it suits direct downloads, lead magnets and printing.

What is the difference between KDP and KDP Select?

KDP is Amazon's self-publishing service for selling books. KDP Select is an optional 90-day programme within it that puts a Kindle ebook into Amazon's reading subscription in exchange for distributing that ebook only through KDP and public libraries.

Do I need an ISBN to self-publish an ebook?

Not on Amazon KDP, where an ISBN is optional for ebooks as of November 2026. Printed books need one, and KDP offers a free ISBN for paperbacks and hardcovers. Other stores have their own requirements.