What Is an Ebook and How Do You Read One?
An ebook is a digital book you read on a screen rather than on paper. It can be a single file (like EPUB or PDF) or a title locked to a store's app (like Kindle books). You read one on a dedicated e-reader, a phone, a tablet, or a computer. The main practical decisions are format, device, and where you get the file — and those three are linked, because not every device opens every format.
Ebook vs. print book vs. audiobook
| Ebook | Print book | Audiobook | |
|---|---|---|---|
| Format | Digital file or app-locked title | Physical object | Digital audio file or stream |
| Reading device | E-reader, phone, tablet, computer | None needed | Phone, tablet, computer, smart speaker |
| How you consume it | Read text on a screen | Read text on paper | Listen |
| Search and notes | Searchable; highlights and notes are usually exportable | Manual | Searchable in some apps |
| Portability | Thousands of titles on one device | Limited by physical space | Same as ebook |
An ebook is not an audiobook. They are separate products, even when a store sells both under one title. Buying the ebook does not normally give you the audiobook, and vice versa.
Common ebook formats and what opens them
The format matters more than anything else when you are choosing a device or an app.
| Format | Typical use | What opens it |
|---|---|---|
| EPUB | The most widely used open ebook format; reflows text to fit the screen | Most e-readers except Kindle, Apple Books, Google Play Books, calibre, many reading apps |
| Fixed layout, good for textbooks, manuals, and scanned documents | Almost anything: browsers, e-readers, phones, computers | |
| MOBI | An older Kindle format | Older Kindle devices and apps; largely superseded |
| AZW3 | A newer Kindle format | Kindle devices and apps |
Two things follow from this table:
- EPUB reflows; PDF does not. On a small phone screen, an EPUB adjusts to the width and stays readable. A PDF keeps its page layout, so you often have to zoom and pan.
- Kindle is the main exception. Kindle devices and apps read Amazon's own formats (AZW3, and now KFX) rather than EPUB directly. If you have an EPUB and want it on a Kindle, you usually convert it first.
Where to get ebooks legally
- Paid stores. Amazon Kindle Store, Apple Books, Google Play Books, Kobo, and publisher-direct shops. You buy a title and read it in that company's app or on its device.
- Public libraries. Many libraries lend ebooks through services like OverDrive/Libby. You need a library card, and popular titles often have waitlists.
- Free and public-domain sources. Project Gutenberg and similar archives offer out-of-copyright titles as EPUB and other formats at no cost.
- Open-source software. calibre is a free, open-source e-book manager. It organizes a library, converts between formats, and can send books to a connected e-reader. It is a tool for managing and converting ebooks you already have — it is not itself a store or a lending service.
A note on "free": free and open-source describe the software (calibre), not the books. Most current commercial ebooks are paid, and library lending requires a card. Do not assume a title is free just because a reader app is.
How to get an ebook onto your device
The steps depend on whether the book is tied to a store or is a file you own.
Store-bought book (simplest path):
- Buy the title in the store's app or website.
- Open the store's app on your phone, tablet, or e-reader.
- The book appears in your library and syncs across devices signed into the same account.
- Expected result: you tap the title and start reading. No file handling needed.
A file you already have (EPUB or PDF):
- Connect your e-reader to your computer by USB, or open your reading app.
- If the device does not support the format, convert it first — calibre can convert between EPUB, MOBI, AZW3, and others.
- Copy or send the file to the device or app.
- Expected result: the title shows up in the device's library and opens.
Sending to a Kindle: Amazon provides a Send-to-Kindle service that accepts files and delivers them to your device. If you have an EPUB, convert it to a Kindle-supported format first, or use a service that converts on upload.
DRM: the limit you will run into
Many commercial ebooks come with DRM (digital rights management), which restricts copying the file to other devices or apps. In practice:
- A DRM-protected book usually works only inside the app or device family you bought it from.
- You generally cannot convert a DRM-protected book to another format with calibre or similar tools.
- DRM-free books — many public-domain titles, some publisher-direct and indie releases — move freely between devices and convert without trouble.
If portability across devices matters to you, check whether a title is DRM-free before buying. That single fact often decides whether a book is easy to manage or locked to one ecosystem.
Managing a personal ebook library
Once you have more than a handful of titles, a manager helps. calibre is the common open-source choice: it stores books in a searchable library, edits metadata (title, author, cover, series), converts formats, and can transfer books to a connected e-reader.
A simple routine that keeps a collection usable:
- Keep one folder as your library and let the manager handle the structure.
- Fill in author and series fields so sorting works.
- Convert to the format your main device reads, and keep the original.
- Back up the library folder — a digital collection is only as safe as its copies.
If your collection has already grown messy, the same steps apply in reverse: import everything into the manager, fix metadata, then convert and transfer only what you are actually going to read.