From Matthew Kirschenbaum’s comments at the Digital Humanities 2010 session on Born-Digital: The 21st Century Archive: Practice and Theory:
From David Levy’s Scrolling Forward (Unlike the Beowulf manuscript, which is an artifact that can accommodate scientific and forensic exploration of aspects of its materiality that have lain dormant for centuries, digital objects are always absolute and finite as representations in the formal sense. As Luciana Duranti has stated, “In the digital realm, we can only persevere our ability to reconstruct or reproduce a document, not the document itself.” Digital preservation, in other words, must model the event conditions that permit future access to a digital work; since there are no artifacts as such in the digital world, only simulations and simulacra, that which is not formally captured and articulated within the preservation model will not be available for subsequent inspection and interpretation.
a digital document, because its perceptible form is always being manufactured just-in-time, on the spot, can’t ever sever its relationship to a set of manufacturing technologies. It requires an elaborate set of technological conditions—hardware and software—in order to maintain a visible and useful presence (152, emphasis in original).