Metadata for OData Services
An OData service is best described using two types of OData Service Metadata documents:
Service Document - The service document serves as the entry point for navigating to the OData service resources. This document lists all of the resources, entity sets, functions and singletons. The service document is typically available at the Base URL in the ATOM or JSON format. For example, this URI http://services.odata.org/V4/TripPinService identifies the service document for a sample OData service.
Metadata Document - The metadata document describes the Entity Data Model (that is, the structure and organization of the OData service resources) exposed as HTTP endpoints by that particular service. This document describes the entity types, entity sets, functions and actions. For example, this URI http://services.odata.org/V4/TripPinService/$metadata identifies the metadata document for a sample OData service.