Beschreibung:
We would like to start this discussion by attempting to make a useful, working distinction between catalogs and databases of astronomical objects. It seems to us that such a distinction could be made based upon the mode of access to the information: A catalog may be considered as a list of objects, almost invariably ordered by coordinates; a database, on the other hand, may be distinguished by its ability to extract a set of objects based on user-given criteria, such as all objects within a certain sky region with magnitudes brighter than m in the blue. Catalogs form the basis of the database, which adds the means of multi-criteria access to the information. In concrete terms, one usually thinks of SIMBAD, NED and LEDA as databases, while an ftp site containing electronic lists of objects may be thought of as a catalog storage warehouse.