In academic publishing, an eprint is a digital version of a research document (usually a journal article, but could also be a thesis, conference paper, book chapter, or a book) that is accessible online, whether from a local institutional, or a central (subject- or discipline-based) digital repository.
When applied to journal articles, the term "eprints" (or "e-prints") covers both preprints (before peer review) and postprints (after peer review).
Digital versions of materials other than research documents are not usually called e-prints, but some other name, such as e-books.