The OSLC provides a set of specifications that service providers implement. They enable clients access to resources managed by the provider. The OSLC specifications are based on open standards an concepts like W3C's linked data, and the Resource Description Framework (RDF). Before a client can start working with a service provider it must first discover the specific REST service end points (URLs) for the particular functionality that the client wishes to exercise.
The OSLC defines two types of 'entry point' resources; Catalogs and Service Providers. A Service Provider resource includes references to the major OSLC services including resource pickers and simple query. It also defines a number pre-defined namespace prefixes (used in OSLC simple queries). A client uses this document to 'discover' these service end points.
When a service provider (like Design Management) hosts a number of projects they are represented by separate Service Provider documents. A Catalog resource is used to list all the service provider resources hosted by the server. A client with a reference only to a host server, may use this document to get a listing of the managed projects to present to a user to select from. Once a specific service provider (eg. project) is selected the client can then get its service document and exercise the REST services on it.