What is an Ebook? What you need to know for Digital Publishing in 2025 - Lacuna Blog

You've written your book. Now you need to turn it into an ebook. But what exactly is an ebook, and why does it matter for your success?

An ebook seems simple - just your book on a screen, right? Not quite. Understanding what makes ebooks work can mean the difference between selling 10 copies or 10,000.

This guide breaks down everything you need to know about ebooks, from basic formats to the technical details that affect your sales.

What Makes Ebooks Different From Regular Books?

An ebook is a digital version of a book you read on phones, tablets, e-readers, or computers. Here are the key differences:

Print Books	Ebooks
Fixed text size	Adjustable fonts - Make text bigger or smaller
One book = space	1,000 books = pocket size - Entire library on one device
Pay for every copy	$0 to duplicate - Sell unlimited copies
Lower royalties	Higher royalties - Keep more profit
Shipping takes days	Instant delivery - Download in seconds
Limited by geography	Sell worldwide - Reach readers in 190+ countries
Can run out of stock	Always available - Never worry about inventory
Returns cost money	No physical returns - Digital files can't be damaged

Your ebook needs proper formatting to display correctly across Kindle, Apple Books, phones, and tablets. Get it wrong, and readers might leave bad reviews.

Which Ebook Format Should You Use?

Most ebooks use one of three formats. Here's what you need to know:

EPUB Is Your Best Friend

EPUB is the universal ebook format that works almost everywhere. But there are two versions:

EPUB 2.0: Start Here

Works on 95% of devices and apps
Perfect for novels and simple non-fiction
Text, basic images, chapter breaks
Best for beginners

EPUB 3.0: For the Fancy Stuff

Everything EPUB 2.0 does, plus:
Interactive elements and multimedia
Better typography and layouts
Great for cookbooks, textbooks, children's books
Use if you need fancy features

Quick decision: Writing a novel or simple how-to book? Go with EPUB 2.0. Creating something with lots of images, videos, or interactive elements? Consider EPUB 3.0.

What About the Others?

Amazon's AZW3: Kindle's format. Based on EPUB but optimized for Amazon. Most publishing tools convert your EPUB to AZW3 automatically.

PDF: Keeps your exact layout but doesn't resize well on phones. Good for workbooks and technical manuals. Not great for novels.

Bottom line: Start with EPUB. Everything else can be converted from there.

How Poorly Formatted Ebooks Cost You Money

Here's what some authors don't know: bad formatting directly impacts your wallet.

Unoptimized Images = Higher Fees

Why This Costs You Money

Amazon, Apple, and other distributors charge you based on how much bandwidth your book uses. Big, unoptimized images = higher fees per download.

Bad Images:
• 15MB ebook file
• $0.15 delivery fee per sale
• Costs you $15 per 100 sales

Optimized Images:
• 2MB ebook file
• $0.02 delivery fee per sale
• Costs you $2 per 100 sales

Bad Metadata = Broken Distribution

What Goes Wrong

Wrong book title formatting: Your title displays incorrectly on devices
Missing author information: Your name doesn't show up properly in stores
No ISBN data: Libraries and bookstores can't catalog your book
Missing accessibility metadata: Screen readers can't navigate your book properly
Broken table of contents: Readers can't jump to chapters on some devices

The Simple Solution

Professional formatting tools like Lacuna handle both of these automatically:

Image optimization: We compress and format images perfectly for every platform
Metadata management: We set up proper titles, author information, ISBNs, and accessibility data correctly

While other authors lose money on delivery fees and struggle with broken distribution, you can focus on writing.

Every Ebook Platform Has Different Rules

Your ebook needs to work on Amazon KDP, Apple Books, Google Play, Kobo, and dozens of other distributors. Each one has different requirements.

If you've never made an ebook file, you may find yourself in a loop of trying to fix bugs in your ebook. Your ebook has to pass validation checks before these platforms will sell it.

Problems You Might Come Across

Before any distributor accepts your book, they run it through EPUB checker tools that scan for:

Broken file structure
Invalid formatting code
Missing required metadata
Images that are too large or in wrong formats
Navigation that doesn't work properly

If your ebook fails these checks, it gets rejected. You'll have to fix the errors and try again.

The Tools Authors Use (And Hate)

A lot of authors use EPUB checkers to help them fix the bugs:

EPUBCheck validator
Ace accessibility checker
Platform-specific validation tools

Running your book through these, fixing errors, re-uploading, checking again... it's a huge learning curve to solve if you've never done it before.

Skip The Technical Headaches

When you format with book formatting software like Lacuna, your ebook automatically passes all the checks. You don't have to worry about it.

Frequently Asked Questions

Why Does Professional Formatting Matter?

Poor formatting leads to platform rejections, bad reviews, and lost sales. Professional formatting tools automatically handle technical requirements so your book displays correctly everywhere.

How Do I Ensure My Ebook Looks Professional?

Use professional software like Lacuna that handles typography, images, metadata, and cross-platform compatibility automatically.

Can I Convert EPUB to PDF Easily?

Yes, but EPUB's flexible text becomes fixed in PDF, which can look bad on small screens. Professional tools handle this conversion better.

When Should I Use PDF vs EPUB?

Use EPUB for novels and most books. Use PDF only for design-heavy content like cookbooks or textbooks where exact layout matters.

Do I Need Special Software for Ebook Creation?

Word processors create basic ebooks, but professional results need specialized software like Lacuna for proper formatting, validation, and multi-platform optimization.

What File Size Should My Ebook Be?

Keep it under 10MB for most books. Larger files cost more in delivery fees and may not work on older devices.

Want Your Ebook Taken Care of For You?

As you can see, there's a lot that goes into making a professional ebook. Everything we discussed in this blog - formats, image optimization, metadata, validation checks - is handled for you automatically in Lacuna.

If you want to try it and you're on Windows, check us out.