An ebook is an electronic (or digital) version of a book. The term is used ambiguously to refer to either an individual work in a digital format, or a hardware device used to read books in digital format. Some users deprecate the second meaning in favour of the more precise "ebook device."

Though e-texts are available as digitally encoded books and the term is often used synonymously with the term ebook, that usage is deprecated. The term e-text is used for the more limited case of data in ASCII text format, while the more general e-book can be in a specialized (and, at times, proprietary) file format. An exception to this rule is the academic e-text, which commonly includes components such as facsimile images, apparatus criticus, and scholarly commentary on the work from one or more editors specially qualified to edit the author or work in question.

An ebook is commonly bundled by a publisher for distribution (as an ebook, an ezine, or a internet newspaper), whereas e-text is distributed in ASCII (or plain text), or in the case of academic works, in the form of discrete media such as compact discs. Metadata relating to the text are sometimes included with etext (though it appears more frequently with ebooks). Metadata commonly include details about author, title, publisher, and copyright date; less common are details regarding language, genre, relevant copyright conventions, etc.