The issues in digital libraries are thus quite similar to those in traditional libraries. Most of the major problems are the same, with some change in orientation due to electronic rather than physical materials. For the foreseeable future, digital libraries are likely to augment physical libraries, much as an on-line card catalog augments, rather than strictly replaces, a book collection. A user's information needs will nearly always be satisfied by some combination of digital and physical materials, each relying on the availability of collections and appropriateness of access. As a rule of thumb, the digital medium tends to be better for searching, and the physical medium tends to be better for reading.
Remote items are more easily available, and relationships between items can be more easily followed.
After much discussion, the research issues for digital libraries were divided into four major categories. The second two deal with the users and the collections support. These issues deal with the global architecture necessary to deploy digital libraries widely. They are primarily at the syntactic level, dealing with the mechanisms for passing digital objects and operations around the network between collections and users. Giving a unique and invariant name to information objects.