The study deals with the concept, the beginning and the development phases of digital library explaining the problem of digital idioms. It sheds light on the requirements and groups of digital library and the technical processes through indexing and classification. In addition to that, the study discuses the mechanism of digital regaining, and explain the ways of search on digital information clarifying the meaning and the mechanism of Boolean logic in search of information. Finally, the paper views the image of Arabic digital libraries and introduces the most important challenges that faces the Arabic digital libraries in the current time. This study ends up to a set of results and recommendations.