Digital libraries can only be viable when a comprehensive digital collection is built. One of the primary methods of doing it is through digitization. Digitization is converting any fixed or analogue media such as books, journal articles, photos, paintings and microforms into electronic form either through scanning, sampling or re-keying.

There are several approaches in deciding what parts of the collection are to be digitized. Complete conversion is ideal but it is quite impractical or technically impossible. More practical alternatives would be the digitization of a particular special collection highlighting a diverse collection, making materials that are in most demand more accessible or digitizing and storing materials as they are requested.