In the past, metadata has always been a second-class citizen in the world of databases and data warehouses. Its main purpose has been to define the data. However, the current emphasis on metadata in the data warehouse and software repository communities has elevated it to a new prominence. The organization now needs metadata for tool integration, data integration and change management.In addition, with the recent Internet expansion, persons all over the world can access more and more document databases. Extensible markup language (XML) is a recently introduced meta-language standard on the Web. It provides the rules for development of metadata (markup) standards for information transfer in specific fields. XML allows development of markup languages that describe what information is rather than how it should be presented. This allows computer applications to process the information in intelligent ways. In contrast hypertext markup language (HTML), which fuelled the initial growth of the Web, XML is a metadata standard concerned exclusively with presentation of information.