Individual users typically connect to the Internet through service providers, local universities, or other organizations at 2.4 Kbps to 28.8 Kbps. With digital technology, it now becomes possible to listen to a book being read, watch a video of a musical performance alongside the original score, or hold a mechanical hand as it forms American Sign Language. Other possible uses are highly personal individuals may dream up many distinct variations. A digital library's presentation systems must be flexible and highly customizable. They must also be aware of the output hardware's capabilities and limitations, automatically adjusting to deliver the best possible presentation quality at all times.
Traditional libraries store a final copy of a book or other documents.
Digital libraries store several versions of a document in a way that makes multiple revisions by multiple authors possible. In addition, the content for a digital library may have multiple owners in terms of the sources of the content and annotations made to the content of the library. An administrative system ensures that materials intended for public viewing can indeed be viewed by anyone while private collections and personal annotations may only be viewed by a select group or single individual. And data-versioning techniques track the history of such revisions. There may also be times when a small group of individuals want access to a portion of digital library content such as when authors are preparing initial drafts of a document.