Catalogue Service for the Web

Catalog Service for the Web (CSW) sometimes seen as Catalog Service - Web is a standard for exposing a catalogue of geospatial records in XML on the Internet (over HTTP). The catalogue is made up of records that describe geospatial data (e.g. KML) geospatial services (e.g. WMS) and related resources.

CSW is one part (or 'profile') of the OGC Catalog Service which defines common interfaces to discover browse and query metadata about data services and other potential resources.

https://en.wikipedia.org/wiki/Catalog_Service_for_the_Web