This chapter presents an architecture for electronic catalogs, called smart catalogs and virtual catalogs. Smart catalogs are searchable, annotated combinations of machine-readable (i.e., minimally processable) and machine-sensible (i.e., actually understood by the computer) product data. Virtual catalogs dynamically retrieve information from multiple smart catalogs and present these product data in a unified manner with their own look and feel, not that of the source smart catalogs. These virtual catalogs do not store product data from smart catalogs directly (except when caching for performance); instead, virtual catalogs obtain current product data from smart catalogs to satisfy specific customer queries. Customers interact with smart catalogs and virtual catalogs through the World Wide Web (WWW) or other interfaces.
