In the digital humanities context, a digital edition is a kind of scholarly edition that is made expressly for digital—usually online—viewing. A scholarly edition is, roughly speaking, a reliable, consistent, and transparently presented version of a text; one that might, for example, note differences between manuscript versions or identify context for passages of the text in footnotes or annotations.
A digital edition may offer more choices than a traditional scholarly edition: for example, you might be able to compare more manuscript versions side-by-side, or turn various kinds of annotation or correction on or off, or link out to further information. Some digital editions might also incorporate multimedia, including sound or video. Digital editions could also engage text analysis or text mining methods to perform comparisons or other tasks.
Key factors in setting out to create a digital edition include securing rights to publish content and finding sustainable web hosting.
Text encoding and hypertext are both concepts that led a great deal of early work in digital humanities, and continue to inflect DH work—especially in digital editions.
Text encoding is the process of labeling every part of a text to reflect its structure in a machine-readable way: so a novel might be broken up into chapters, then paragraphs, then sentences; poetry might be broken up into stanzas and lines. This is usually done in a markup language—such as HTML (HyperText Markup Language) or XML (Extensible Markup Language)—but text encoding predates the Internet. Many of the goals of early text encoders now fall under text mining (identifying patterns in texts, for example, or connections between them).
Hypertext is text that links out to other relevant texts: think about the many cross-references in Wikipedia, for example. Hypertext is the other half of HTML; web documents are structured, labeled texts that link to other texts. As with text encoding, though, hypertext is a concept that predates the Internet.
These ideas—of documents that are carefully labeled and interconnected by links—shape many digital editions, especially those designed specifically and from the start for online publication.