E-books are digital publications. They are books made to be read on a screen, such as a computer, tablet, phone, or e-reader. An e-book may contain text, images, links, audio, or video. It may also be an electronic copy of a printed book.
This answer seems simple, but search work adds an important point. An e-book is the content, not the device used to read it. A Kindle, tablet, or reading app is only a tool for access. The book itself is a digital file or a digital text made available through a website, library service, or other platform.
That difference matters when a catalog record says “e-book.” The label does not tell the whole story. It may describe a scanned book, a born-digital book, a PDF, an EPUB file, or a book that can only be read inside a platform. These forms may look alike to a reader, but they work in different ways.
A PDF often keeps the page design of the printed book. This can help when page numbers, charts, or notes matter. An EPUB usually allows the text to adjust to the screen. Font size and spacing can change, and the text can reflow. HTML books display text through a web browser and may work well with screen readers and other access tools.
The format affects research. A searchable PDF may allow a reader to find a word in the text. A scanned PDF may show page images without usable text. In that case, the search depends on optical character recognition, or OCR. OCR turns an image of printed words into computer-readable text. It can make searching possible, but it can also make errors.
This is where the phrase “full-text search” needs care. Full text means the words inside the book can be searched. It does not mean every e-book has this feature. Some library systems search only the record for a book. That record contains metadata, or information about the item, such as its title, author, publisher, date, and subject.
A catalog may therefore find a book because its subject terms match a query. It may not find a book that contains the exact word being sought. Other platforms search both metadata and book text. Their results can still vary because access rules, file types, and text quality differ.
The difference between record searching and full-text searching is easy to miss. A search for “memory” might find books with memory in the title or subject field. It might also find books where the word appears many times in the text. Those are different kinds of results. A researcher needs to know which kind the platform returns.
Search tools also differ within one e-book platform. Some allow searches across a whole collection. Others search one book at a time. Some show only a short passage around a match. Some allow page viewing but restrict copying or downloading. These limits are part of the source, not small technical details.
Digital rights management, often called DRM, can control how a book is used. It may tie access to an account, app, or device. It may limit printing, copying, downloading, or the length of time a file can be used. A book can therefore be digital without being freely portable or fully open.
This point needs a plain statement. Digital does not mean open access. It also does not mean permanent access. A library may provide an e-book through a license rather than own a file that can be kept without limits. The exact terms depend on the publisher, platform, and collection.
Accessibility adds another concern. HTML text can often be enlarged and read by screen-reading software. A well-made EPUB can also adjust to different screens. A fixed PDF or scanned page may be harder to use, especially when the text layer is missing or poorly made. Format alone does not prove that a book is accessible, but format is one important factor.
I pause here because “e-book” can sound like a stable category. It is not always stable in practice. Publishers and libraries may use the term for many forms of digital book. A platform may change its reader, download rules, or search tools after a guide has been written. A current record is useful, but it may not describe every limit a reader will meet.
The safest search habit is to separate three questions. What book is this? What part of the book can be searched? What can be done with the text after it is found? The first question concerns the record. The second concerns full-text access. The third concerns reading, copying, downloading, and saving.
This habit also helps with citations. An e-book may have page numbers that match the print edition. It may instead use location numbers, chapter sections, or screen positions. A citation method that works for one format may not work for another. The book record and the reader interface may provide different details.
An e-book can also be created without a print version. Digital publication is not limited to scanned books or electronic copies of paper books. Some books begin as digital files and use links, media, or other features that print cannot carry in the same way. Still, the central fact stays clear: an e-book is a book published in digital form.
The useful source is not simply the one that says “e-book.” It is the one that states what the book contains, how it can be searched, and what limits apply. A catalog record may identify the work. A platform guide may explain access. A file format may shape reading and search. These pieces belong together.
For search work, the honest limit is that the label alone cannot answer all of these questions. Coverage, text quality, search scope, and user rights may remain unclear until the publisher or library documents them. When that information is missing, the record should be treated as incomplete rather than precise.
That is the small lesson behind this large category: an e-book is a digital publication, but its research value depends on how that publication is built and supplied. The Source List follows the same rule with one digital source worth knowing, one search tip, and one honest limitation.