OData (Open Data Protocol) is a Web protocol for querying and updating data that provides a way to unlock data and free it from restrictions that exist in applications today. Since OData applies Web technologies, it enables you to access information from a variety of applications, services, and stores and thus assures interoperability across a broad range of clients, servers, services, and tools. OData is being used to expose and access information from a variety of sources including, but not limited to, relational databases, file systems, content management systems, and traditional Web sites. It uses URIs to identify resources and uses an HTTP-based uniform interface for interacting with those resources.
For more information, see the Web sites of the Open Data Protocol.