Metadata, or the need to label, categorize and describe structured information, so that digital documents can process, store, preserve, retrieve and exchange through the World Wide Web, will star certainly a new paradigm in systems and information services if glo xxi. This topic has aroused great interest and scientific debate in the international library community and around the emerging field of electronic information systems, due to the evidence of the Internet as a source, reservoir and source of information, as well as new forms of register knowledge involved the explosion of digital information. All these changes have challenged traditional methods of information processing (cataloging, classification and indexing), and impose a strategic redefinition of the role of manager information with the digital library.