摘要：There is a consensus within the Geographical Information (GI) Community in the metadata and data capture and management process and of technological development - in particular those concerning intelligent tools, intelligent search engines - that metadata content and services are really necessary to increase the visibility of the existing content and to facilitate access by users to geographical information. In our paper dedicated to "MEDIAGIS Project" presented in 7th EC GI&GIS Workshop, we discussed about On Line Service for Geographical Information focused on a general architecture. In this context we mentioned the four levels of complexity of this service: metainformation, transactional, integration, new opportunities. The development of Metadata is very important for all levels presented here. This paper is not an original paper in the real sense of word but try to present a synthetically point of view regarding the metadata and their development in the framework of On Line Service in the context of Virtual Communities specific for Information Society. The fourth sections try to answer what is metadata, why metadata, how to create metadata and what kind of information resources it will be necessary and/or recommendable to use in the framework of metadata services according to users requirements and why use standards and make a short overview of geospatial standards and initiatives. and what tools are available to do this. The last section is dedicated to the conclusions and to the situation at European level and try to answer.
关键词：data access; data dissemination; metadata culture; metainformation; Geographical;Information (GI); Geographical Information System (GIS); clearinghouse; education; social;networks; level of users; coverage of data and quality of metadata; updating; searching;and navigation facilities; best practices; metadata service providers; geospatial standards.
