the other hand, preservation of digital materials is not a straightforward matter in light of media fragility and system and format obsolescence.

Approaches to preserving digital material include migration of existing digital material to new software and hardware platforms as necessitated by new technology; development of emulators of obsolete hardware and software systems to permit continued access; and development and adoption of long-term standards and descriptive formats with longer life spans. Once digital material has been archived, another key challenge is to construct search and retrieval systems to facilitate access.